Equipment
Ingredients
Cupcake Batter
- 125 g all-purpose flour
- 100 g granulated sugar
- 100 g dark brown sugar, packed
- 40 g cocoa powder, unsweetened
- 4 g baking soda
- 2 g baking powder
- 3 g salt
- 120 ml vegetable oil
- 120 ml buttermilk, room temperature
- 1 egg, large, room temperature
- 5 ml vanilla extract
- 120 ml hot water, freshly boiled
Peanut Butter Frosting
- 115 g unsalted butter, softened to room temperature
- 250 g creamy peanut butter, conventional, not natural or separated
- 180 g powdered sugar, sifted if clumpy
- 30 ml heavy cream, cold
- 5 ml vanilla extract
- 3 g flaky sea salt
Nutrition (per serving)
Method
Preheat your oven to 175°C (350°F). Line a 12-cup muffin tin with paper liners.
In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, dark brown sugar, cocoa powder, baking soda, baking powder, and salt until completely uniform and free of lumps.
In a separate medium bowl, mix the vegetable oil, buttermilk, egg, and vanilla extract until thoroughly combined.
Pour the wet ingredients into the dry ingredients and stir gently until just combined. Do not overmix.
Carefully stir the freshly boiled hot water into the batter. The mixture will become very thin, which is exactly right for a light crumb.
Divide the batter evenly among the 12 cupcake liners, filling each about two-thirds full. Bake at 175°C (350°F) for 18 to 20 minutes, or until a toothpick inserted into the center comes out clean.
Allow the cupcakes to cool in the tin for 5 minutes, then transfer them to a wire cooling rack to cool completely before frosting.
To make the frosting, use an electric mixer to beat the softened butter and creamy peanut butter in a mixing bowl on medium speed until perfectly smooth and well blended, about 2 minutes.
Add the powdered sugar, heavy cream, vanilla extract, and flaky sea salt to the peanut butter mixture. Beat on low speed until incorporated, then increase the speed to medium-high and whip for 3 minutes until light and fluffy.
Generously pipe or spread the peanut butter frosting onto each fully cooled cupcake. Garnish with an extra pinch of flaky sea salt just before serving.
Chef's Notes
- Using hot water at the end of the batter mixing process blooms the cocoa powder, releasing complex flavor compounds that dramatically intensify the chocolate taste.
- Vegetable oil is 100 percent fat, whereas butter contains water. Oil coats flour proteins better, inhibiting gluten formation and ensuring these cupcakes stay incredibly tender and moist for several days at room temperature.
- Always use conventional peanut butter like Jif or Skippy for the frosting. Natural peanut butters that separate in the jar will cause the delicate frosting emulsion to break and become unpleasantly greasy.
- The batter will seem alarmingly thin after adding the hot water. Trust the process; this high-hydration batter is the exact secret to a featherlight crumb that rises beautifully.
Storage
Refrigerator: 5 days — Bring to room temperature for 30 minutes before serving so the frosting softens.
Freezer: 3 months — Freeze unfrosted cupcakes wrapped tightly in plastic wrap. Frosting can also be frozen separately.
