Quick Recipe Version (TL;DR)

Yield: 10 slices (1 standard loaf, 9 x 5 in / 23 x 13 cm pan)
Prep Time: 20 minutes
Cook Time: 55 minutes
Total Time: 1 hour 15 minutes (plus cooling)

Quick Ingredients

1 1/2 cups (190 g) all-purpose flour
1/2 cup (45 g) unsweetened cocoa powder
1 1/2 tsp baking powder + 1/2 tsp baking soda + 1/2 tsp fine salt
3/4 cup (170 g) unsalted butter, softened
1 cup (200 g) granulated sugar
2 large eggs + 1 large egg yolk (room temperature)
2 tbsp finely grated orange zest (about 2 large oranges)
2 tsp vanilla extract
1/2 cup (120 g) full-fat sour cream (room temperature)
1/4 cup (60 ml) freshly squeezed orange juice (plus 1/4 cup more for syrup)
2 tbsp (30 ml) neutral oil
Orange marmalade (about 2 tsp–1 tbsp total, for syrup and glaze)
1/4 cup (50 g) sugar for syrup
1 cup (120 g) powdered sugar + 1 tbsp cocoa for glaze

Do This

1. Preheat oven to 350°F (175°C). Grease and line a 9 x 5 in (23 x 13 cm) loaf pan with parchment.
2. Whisk flour, cocoa, baking powder, baking soda, and salt in a bowl.
3. Beat butter and sugar until fluffy; mix in eggs, yolk, orange zest, and vanilla.
4. Stir sour cream, 1/4 cup orange juice, and oil together; mix into batter alternately with dry ingredients. Spread into pan.
5. Bake 50–60 minutes until a skewer comes out with just a few moist crumbs. Cool 10–15 minutes in pan.
6. Simmer 1/4 cup orange juice, 1/4 cup sugar, and 1 tbsp marmalade to make syrup; brush over warm loaf and let cool completely.
7. Whisk powdered sugar, cocoa, a little orange juice, and marmalade into a pourable glaze; drizzle over cooled cake, slice, and serve.

Why You’ll Love This Recipe

Deep, cozy chocolate flavor balanced with bright, fresh orange zest and juice.
Moist, tender crumb thanks to sour cream and a touch of oil, so it stays soft for days.
A simple orange-marmalade syrup soaks the warm loaf for a subtle, jammy finish.
Perfect for afternoon tea, weekend baking, or a make-ahead dessert that slices beautifully.

Grocery List

Produce: 2–3 large oranges (for zest, juice, and optional garnish)
Dairy: Unsalted butter, sour cream (or full-fat Greek yogurt), eggs
Pantry: All-purpose flour, unsweetened cocoa powder, granulated sugar, powdered sugar, baking powder, baking soda, fine salt, vanilla extract, neutral oil, orange marmalade, optional orange liqueur (Cointreau, Grand Marnier)

Full Ingredients

Chocolate Orange Loaf Cake

1 1/2 cups (190 g) all-purpose flour
1/2 cup (45 g) unsweetened cocoa powder, sifted
1 1/2 tsp baking powder
1/2 tsp baking soda
1/2 tsp fine sea salt
3/4 cup (170 g) unsalted butter, softened to room temperature
1 cup (200 g) granulated sugar
2 large eggs, at room temperature
1 large egg yolk, at room temperature
2 tbsp finely grated orange zest (from about 2 large oranges)
2 tsp pure vanilla extract
1/2 cup (120 g) full-fat sour cream or full-fat Greek yogurt, at room temperature
1/4 cup (60 ml) freshly squeezed orange juice
2 tbsp (30 ml) neutral-tasting oil (such as canola, sunflower, or grapeseed)

Orange Marmalade Syrup

1/4 cup (60 ml) freshly squeezed orange juice
1/4 cup (50 g) granulated sugar
1 tbsp fine-cut orange marmalade
Optional: 1 tsp orange liqueur (Cointreau or Grand Marnier), added off the heat

Chocolate Orange Glaze

1 cup (120 g) powdered (confectioners’) sugar, sifted
1 tbsp (7 g) unsweetened cocoa powder, sifted
1–2 tbsp (15–30 ml) freshly squeezed orange juice, as needed for consistency
1 tsp fine-cut orange marmalade, very finely chopped or pressed through a sieve (optional, for a subtle marmalade note)
Pinch fine sea salt

Optional Garnish

Extra finely grated orange zest or very thin strips of orange peel
Dark chocolate curls or shavings

Step-by-Step Instructions

Step 1: Prepare the pan and preheat the oven

Preheat your oven to 350°F (175°C), with a rack in the center. Lightly grease a 9 x 5 in (23 x 13 cm) loaf pan with butter or nonstick spray. Line the bottom and long sides with a strip of parchment paper, leaving a little overhang to help lift the loaf out later. Lightly grease the parchment as well. This helps prevent sticking and gives the loaf clean, sharp edges.

Step 2: Mix the dry ingredients

In a medium bowl, whisk together the flour, cocoa powder, baking powder, baking soda, and salt until well combined and no streaks remain. Sifting the cocoa (and powdered ingredients, if you like) helps avoid lumps and keeps the crumb tender. Set this bowl aside; you will add it to the wet ingredients in batches.

Step 3: Cream the butter, sugar, eggs, and orange zest

In a large mixing bowl (or the bowl of a stand mixer fitted with the paddle attachment), beat the softened butter and granulated sugar together on medium speed for about 3–4 minutes, until the mixture looks pale and fluffy. Scrape down the sides of the bowl once or twice to make sure everything is evenly mixed.

Add the eggs and egg yolk one at a time, beating well after each addition. The batter may look slightly curdled at first; keep mixing and it will smooth out. Beat in the orange zest and vanilla until evenly distributed and fragrant. At this point, the mixture should smell strongly of orange and vanilla.

Step 4: Combine the wet ingredients and bring the batter together

In a small bowl or measuring jug, whisk together the sour cream, 1/4 cup (60 ml) orange juice, and neutral oil until smooth. This mixture adds moisture and richness so the loaf stays soft and tender rather than dry.

With the mixer on low speed (or using a spatula), add about one third of the dry ingredients to the butter mixture and mix just until combined. Add half of the sour cream/orange juice mixture and gently mix again. Continue alternating dry ingredients and sour cream mixture, ending with the dry ingredients (dry–wet–dry–wet–dry). Stir only until you no longer see streaks of flour. Overmixing at this stage can make the loaf tough, so stop as soon as the batter is smooth and evenly chocolatey.

Use a spatula to scrape the bowl and give the batter a final gentle fold to make sure everything is incorporated from the bottom and sides.

Step 5: Bake the loaf

Scrape the batter into the prepared loaf pan and smooth the top with a spatula or the back of a spoon. If you like, you can gently tap the pan on the counter once or twice to knock out large air bubbles.

Bake in the preheated oven for 50–60 minutes, or until the top is risen and slightly cracked and a skewer or thin knife inserted into the center comes out with just a few moist crumbs (no wet batter). Start checking around the 48–50 minute mark, as all ovens are a little different.

Once baked, transfer the pan to a wire rack and let the cake cool in the pan for 10–15 minutes while you prepare the syrup.

Step 6: Make the orange marmalade syrup and soak the warm loaf

While the loaf is resting, make the syrup. In a small saucepan, combine 1/4 cup (60 ml) orange juice, 1/4 cup (50 g) sugar, and 1 tbsp orange marmalade. Heat over medium-low, stirring often, until the sugar is dissolved and the mixture comes to a gentle simmer. Let it bubble softly for 1–2 minutes to slightly thicken. Remove from the heat. If using, stir in the orange liqueur now.

Using a skewer or thin knife, poke several small holes all over the top of the warm cake, going most of the way down but not piercing the bottom. Slowly spoon or brush the hot syrup over the surface, letting it soak in as you go. The loaf will look shiny and slightly sticky on top, with a lovely citrus aroma.

Once the syrup has absorbed, carefully lift the loaf out of the pan using the parchment overhang and place it on a wire rack to cool completely, at least 1 hour. The glaze should only go on a fully cooled cake.

Step 7: Glaze, garnish, and serve

When the loaf is completely cool to the touch, make the glaze. In a medium bowl, whisk together the powdered sugar, cocoa powder, and salt. Add 1 tbsp orange juice and whisk until smooth. Add a little more orange juice, a few drops at a time, until you have a thick but pourable glaze that slowly ribbons off the spoon. If using, whisk in the finely chopped marmalade for a subtle marmalade speckle and flavor.

Place the cooled loaf on a serving platter (slipping pieces of parchment under the edges if you want easy cleanup). Pour or spoon the glaze over the top of the loaf, letting it drip naturally down the sides. While the glaze is still soft, sprinkle with a little extra orange zest or very thin orange peel strips, and a few dark chocolate curls if you like.

Let the glaze set for about 20–30 minutes before slicing with a sharp serrated knife. Wipe the knife between slices for the cleanest cuts. Serve slightly warm or at room temperature.

Pro Tips

Use room temperature ingredients. Soft butter, room temp eggs, and sour cream blend more easily, giving you a smoother batter and a finer, more even crumb.
Do not overmix once the flour goes in. Stir just until no dry streaks remain. Overmixing can develop the gluten and make the loaf dense instead of tender.
Check doneness early. Start checking at 48–50 minutes; if your oven runs hot, the loaf may be done sooner. A few moist crumbs on the skewer are perfect.
Adjust the glaze thickness. If the glaze is too runny, add a spoonful more powdered sugar; if it is too thick to drizzle, add a few drops more orange juice.
Make it extra orangey. For a stronger citrus hit, add an extra teaspoon of finely grated zest to the batter or use the optional orange liqueur in the syrup.

Variations

Dark chocolate chip version: Fold 1/2–3/4 cup (85–130 g) dark chocolate chips or chunks into the finished batter before baking for pockets of melted chocolate throughout the loaf.
Marmalade swirl loaf: After spreading the batter into the pan, dollop 2–3 tbsp orange marmalade on top and gently swirl it through with a knife for visible ribbons of jammy orange.
Mini loaves or muffins: Bake the batter in 2–3 mini loaf pans or a standard muffin tin (lined) at 350°F (175°C). Check muffins at about 18–22 minutes and mini loaves at 25–30 minutes.

Storage & Make-Ahead

Once completely cooled and glazed, store the loaf in an airtight container at room temperature for up to 3–4 days. The flavors actually deepen by the next day as the orange and cocoa mingle. For longer storage, wrap the unglazed loaf tightly in plastic wrap and then foil, and freeze for up to 2–3 months. Thaw overnight in the fridge or at room temperature (still wrapped), then add the glaze just before serving. Leftover slices can also be individually wrapped and frozen for quick treats; gently warm or bring to room temperature before enjoying.

Nutrition (per serving)

Approximate values per slice (1 of 10): about 400–430 calories, 20–22 g fat, 55–60 g carbohydrates, 4–5 g protein, and 32–36 g sugar. Actual values will vary based on specific ingredients used and the amount of glaze and syrup absorbed.

Moist Chocolate Orange Loaf Cake with Citrus Zest