Salted Butterscotch Rum Sauce

Why You’ll Love This Recipe

• Deep, buttery toffee flavor in 15–20 minutes, start to finish.
• Glossy, pourable sauce that stays silky as it cools.
• Adjustable: choose the salt level and rum intensity you love.
• Perfect for drizzling over bread pudding, bananas, apple crisp, or ice cream.

Grocery List

• Produce: None
• Dairy: Unsalted butter; heavy cream
• Pantry: Dark brown sugar; pure vanilla extract; dark rum; flaky sea salt (optional: light corn syrup or golden syrup)

Full Ingredients

Salted Butterscotch Rum Sauce

• 1 cup (200 g) packed dark brown sugar (light brown works for a milder flavor)
• 6 Tbsp (85 g) unsalted butter, cut into 1/2-inch pieces
• 1/2 cup (120 ml) heavy cream, warmed to lukewarm
• 1 1/2 tsp pure vanilla extract
• 1 Tbsp (15 ml) dark rum, plus up to 1 Tbsp more to taste
• 1/2 to 3/4 tsp flaky sea salt, plus a pinch for finishing
• (Optional) 1 tsp light corn syrup or golden syrup for extra-smooth sauce

Step-by-Step Instructions

Step 1: Warm the cream and set up

Measure all ingredients before you begin. Warm the heavy cream in a small saucepan or microwave just until lukewarm; this helps prevent splattering and keeps the sauce silky. Set a medium (2–3 quart) heavy-bottomed saucepan on the stove and have a whisk ready.

Step 2: Melt butter and brown sugar

Add the butter and brown sugar to the saucepan. Cook over medium heat, whisking steadily as the butter melts and the mixture turns glossy and uniform with no visible sugar crystals.

Step 3: Bubble to build butterscotch flavor

Once smooth, let the mixture come to a steady bubble. Continue cooking, stirring occasionally, for 3 to 4 minutes. It should smell deeply caramelized and look thick and shiny. Keep the heat moderate to avoid scorching.

Step 4: Carefully whisk in the cream

Remove the pan from heat and pour in the warm cream in a slow, steady stream while whisking constantly. The mixture will bubble up vigorously—this is normal. Return the pan to medium heat and whisk until completely smooth.

Step 5: Simmer to desired thickness

Simmer for 2 to 3 minutes more, stirring frequently, until the sauce is glossy and lightly thickened. For precision, aim for 225–230°F (106–110°C). The sauce will thicken further as it cools; stop toward the thinner side if you prefer a pourable finish.

Step 6: Finish with vanilla, rum, and salt

Remove from heat. Whisk in the vanilla, 1 Tbsp rum, and 1/2 tsp flaky sea salt. Taste and add more salt (a pinch at a time) and, if desired, up to 1 more Tbsp rum. For a less boozy finish, return to low heat for 30 seconds after adding rum.

Step 7: Strain, cool briefly, and serve

For ultra-smooth sauce, strain through a fine-mesh sieve into a heatproof jar or small pitcher. Let cool 10 minutes to thicken slightly. Sprinkle with a few extra flakes of salt just before serving. Drizzle warm over desserts or keep in jars for gifting.

Pro Tips

• Use dark brown sugar for a deeper molasses note; light brown sugar yields a lighter, butterscotch flavor.
• Warm cream prevents curdling and reduces violent bubbling when added.
• If the sauce separates or looks oily, whisk in 1 to 2 tsp warm cream off heat to re-emulsify.
• Thicker sauce: cook 1 minute longer or to the higher end of 230°F; thinner sauce: pull at 225°F.
• Flaky finishing salt adds pops of texture; avoid fine table salt for finishing, which can taste harsh.

Variations

• Rum-Free: Swap rum for 1 Tbsp apple cider or extra cream plus a pinch more vanilla.
• Miso Butterscotch: Whisk in 1 to 2 tsp white miso with the vanilla for a savory-sweet depth.
• Espresso Butterscotch: Stir in 1 tsp instant espresso powder (or 1 Tbsp strong brewed espresso) with the vanilla.

Storage & Make-Ahead

Refrigerate in a sealed jar up to 2 weeks. Rewarm gently in a saucepan over low heat or in short microwave bursts, stirring often; add a splash of cream if needed to loosen. Freeze up to 3 months; thaw overnight in the refrigerator and rewarm gently before serving.

Nutrition (per serving)

Approximate per 2 Tbsp: 180 calories; 11 g fat (7 g saturated); 21 g carbohydrates; 20 g sugars; 0 g protein; 140 mg sodium. Values are estimates and will vary based on exact ingredients and salt level.