Dr. Pepper Cake

Preheat oven to 375°F. Lightly grease a 9x13-inch metal baking pan with cooking spray.

Combine the dry ingredients: In a large bowl, whisk together the flour, baking soda, salt, cinnamon, and ginger. Set it aside.

Make the cake batter: Melt the butter in a medium saucepan over low heat. Once the butter is melted, whisk in the sugar, 1 cup Dr. Pepper, and cocoa. Bring to a rolling boil over medium-high heat, stirring occasionally. Remove from the heat. Immediately add the flour mixture and whisk to combine until no lumps remain. Stir in the buttermilk, then the eggs and vanilla until the mixture is smooth.

Bake: Pour the batter into the prepared pan. Bake until a toothpick inserted into the center comes out clean, 25 to 30 minutes.

Make the icing: About 10 minutes before the cake is done baking, prepare the icing. Heat the remaining 1/2 cup Dr. Pepper in a medium saucepan over high heat and simmer until reduced to about 1 tablespoon and it coats the back of a spoon, about 5 minutes. Add the butter and stir until melted and smooth. Once the butter is melted, whisk in the powdered sugar, vanilla, salt, and cinnamon until smooth, about 30 seconds. Whisk in the buttermilk, 1 tablespoon at a time, until a smooth, thick glaze forms, 30 seconds to 1 minute. Remove from the heat and set aside until ready to use, stirring occasionally. Keep warm.

Ice the cake: Transfer the baked cake to a wire rack to cool slightly for about 10 minutes. Pour the icing over the cake while both are warm, swiftly using a silicone spatula to spread the icing out evenly—it will cool and harden quickly. Serve warm or at room temperature. Store leftover cake in an airtight container in the fridge for up to a week.