Ingredients

• ¾ cup whole-wheat pastry flour

• ⅔ cup granulated sugar

• ½ cup cocoa powder

• ½ teaspoon baking soda

• ½ teaspoon instant espresso powder

• ¼ teaspoon salt

• ⅔ cup neutral oil, such as canola or avocado

• ½ cup whole-milk plain strained (Greek-style) yogurt

• ½ cup whole buttermilk

• 1 teaspoon vanilla extract

• 1 large egg, at room temperature

• ¾ cup unsalted smooth natural peanut butter

• ½ cup unsalted butter, softened

• 1 cup confectioners’ sugar

• 1 teaspoon vanilla extract

• Pinch of salt

• Chopped unsalted roasted peanuts for garnish (optional)

• Bittersweet chocolate curls for garnish (optional)