Soft Vanilla Bars With Caramelized Nutella Swirls

Why You’ll Love This Recipe

• Soft, vanilla-scented bars marbled with rich ribbons of Nutella that caramelize at the edges.
• Simple pantry ingredients and one bowl for the batter make this very weeknight-friendly.
• Perfectly portable: great for bake sales, picnics, potlucks, or lunchbox treats.
• Easy to customize with toppings like flaky sea salt or crunchy hazelnuts.

Grocery List

• Produce: None needed
• Dairy: Unsalted butter, whole milk, large eggs
• Pantry: Nutella (or chocolate-hazelnut spread), all-purpose flour, granulated sugar, light brown sugar, pure vanilla extract, baking powder, fine sea salt, optional flaky sea salt, optional hazelnuts

Full Ingredients

For the Vanilla Bar Batter

• 1/2 cup (115 g) unsalted butter, melted and slightly cooled
• 1/2 cup (100 g) granulated sugar
• 1/2 cup (100 g) light brown sugar, packed
• 2 large eggs, at room temperature
• 2 tsp pure vanilla extract
• 1 1/4 cups (155 g) all-purpose flour, spooned and leveled
• 1/2 tsp baking powder
• 1/2 tsp fine sea salt (or table salt)
• 1/4 cup (60 ml) whole milk, at room temperature

For the Nutella Swirl

• 3/4 cup (225 g) Nutella or other chocolate-hazelnut spread

Optional Garnish

• Flaky sea salt, for sprinkling on top after baking
• 2–3 tbsp chopped toasted hazelnuts, for extra crunch (optional)

Step-by-Step Instructions

Step 1: Prep the pan and preheat the oven

Preheat your oven to 350°F (175°C) with a rack in the center position. Lightly grease an 8-inch (20 cm) square baking pan with butter or nonstick spray. Line the bottom and two sides with a sheet of parchment paper, leaving a bit of overhang on opposite sides to create a sling. This makes it easy to lift the bars out cleanly for slicing. Lightly grease the parchment as well.

Step 2: Melt the butter and gather ingredients

Melt the butter in a small saucepan over low heat or in a microwave-safe bowl in 20–30 second bursts. Set aside to cool until just warm, not hot, so it does not scramble the eggs. While it cools, measure out all remaining ingredients. For the best texture, make sure the eggs and milk are at room temperature; this helps the batter mix smoothly and bake evenly.

Step 3: Make the vanilla batter

In a medium mixing bowl, whisk together the melted, slightly cooled butter, granulated sugar, and brown sugar until the mixture looks glossy and well combined, 30–60 seconds. Add the eggs one at a time, whisking well after each addition until the batter looks thick and smooth. Whisk in the vanilla extract.

In a separate small bowl, whisk the flour, baking powder, and salt together so the leavening is evenly dispersed. Using a spatula or wooden spoon, stir the dry ingredients into the wet mixture in two additions, alternating with the milk. Mix just until no streaks of dry flour remain. The batter will be thick and silky.

Step 4: Spread the batter in the pan

Scrape the vanilla batter into the prepared pan. Use an offset spatula or the back of a spoon to spread it into an even layer, pushing it gently into all four corners. Level the top as much as possible; a smooth surface makes it easier to create pretty Nutella swirls.

Step 5: Add and swirl the Nutella

Place the Nutella in a microwave-safe bowl and warm it in 10–15 second bursts, stirring between each, just until it is loosened and pourable but not hot. You can also warm the jar in a bowl of hot tap water for a few minutes.

Using a spoon, drop the warmed Nutella all over the surface of the batter in generous dollops and thin ribbons. Aim for 10–14 spoonfuls rather than one big pool; this gives you better marbling. Drag the tip of a butter knife or skewer through the Nutella and batter in gentle figure-eight motions to create a marbled pattern. Try not to over-swirl or you will lose the defined ribbons—2–3 passes in each direction is plenty.

Step 6: Bake until just set

Transfer the pan to the center rack and bake for 22–25 minutes, or until the edges are lightly golden and a toothpick inserted into the vanilla portion (avoid the Nutella pockets) comes out with a few moist crumbs but no wet batter. The Nutella ribbons will look glossy and slightly puffed, and the bars will continue to set as they cool. If you prefer gooier centers, aim for the shorter end of the baking time.

Step 7: Cool, garnish, and slice

Place the pan on a wire rack and let the bars cool in the pan for at least 30 minutes and up to 1 hour. For the cleanest slices, wait until they are just slightly warm or completely cool. If desired, sprinkle a pinch of flaky sea salt over the top while still a bit warm, and scatter on chopped toasted hazelnuts for crunch.

Use the parchment sling to lift the slab of bars out of the pan and onto a cutting board. With a sharp knife, cut into 16 squares (4 by 4) or 12 larger rectangles. Wipe the knife between cuts for neat edges that show off the Nutella swirls.

Pro Tips

• Do not overbake: These bars are best when the centers stay soft and just set. Pull them out as soon as the edges are golden and the middle barely jiggles.
• Warm but not hot Nutella: If the Nutella is too thick, it will clump instead of swirl. If it is too hot, it will melt into the batter. Aim for pourable and silky.
• Measure flour carefully: Too much flour makes dense, dry bars. Spoon flour into your measuring cup and level it off, or use the gram measurement for accuracy.
• Room temperature eggs and milk: Cold ingredients can cause the melted butter to firm up and make the batter lumpy. Let them sit out for 20–30 minutes before baking.
• Chill for ultra-clean slices: If you want perfect bakery-style squares, chill the cooled slab for 30 minutes, then slice and bring back to room temperature before serving.

Variations

• Salted Nutella Bars: Increase the flaky sea salt topping for a more pronounced sweet-salty contrast. Sprinkle a light pinch over the whole pan immediately after baking.
• Hazelnut Crunch: Fold 1/3 cup (40 g) chopped toasted hazelnuts into the batter before spreading it in the pan, then add another sprinkle on top after baking.
• Extra Chocolatey Swirl: Swirl 1/2 cup (120 g) Nutella with 1/4 cup (45 g) mini chocolate chips sprinkled over the top before baking for pockets of melted chocolate.

Storage & Make-Ahead

Let the bars cool completely before storing. Keep them in an airtight container at room temperature for up to 3 days. For longer storage, refrigerate them for up to 5 days; bring to room temperature before serving for the best texture. To freeze, wrap individual bars tightly in plastic wrap, then place in a freezer-safe bag or container for up to 2 months. Thaw at room temperature (about 1 hour) or overnight in the refrigerator. These bars can also be baked a day ahead; in fact, the flavor often deepens by the next day.

Nutrition (per serving)

Approximate values for 1 of 16 bars: about 230 calories, 12 g fat, 28 g carbohydrates, 2 g fiber, 20 g sugars, 3 g protein, and 160 mg sodium. Actual values will vary based on specific brands and portion sizes.