01 -
Preheat your oven to 350°F (175°C). Line a standard 12-cup muffin tin with paper cupcake liners.
02 -
In a medium bowl, whisk together the flour, cocoa powder, baking soda, and salt until well combined. Set aside.
03 -
In a large bowl, whisk together the melted butter and brown sugar until smooth. Add the eggs one at a time, beating well after each addition. Stir in the vanilla extract, buttermilk, and mashed blackberries until combined.
04 -
Gradually add the dry ingredients to the wet ingredients, mixing gently until just combined. Do not overmix.
05 -
Slowly pour in the hot coffee or hot water, stirring until the batter is smooth. The batter will be thin, which is normal.
06 -
Divide the batter evenly among the cupcake liners, filling each about ¾ full.
07 -
Bake in the preheated oven for 18-22 minutes, or until a toothpick inserted into the center of a cupcake comes out clean or with just a few moist crumbs.
08 -
Remove from the oven and let the cupcakes cool in the pan for 5 minutes, then transfer to a wire rack to cool completely before frosting.
09 -
While the cupcakes are cooling, prepare the blackberry purée for the frosting. Blend fresh blackberries in a blender or food processor until smooth, then strain through a fine-mesh sieve to remove the seeds, pressing with a spoon to extract all the juice.
10 -
In a large bowl, beat the softened butter with an electric mixer until creamy, about 2 minutes. Gradually add the powdered sugar, mixing on low speed until incorporated. Add the strained blackberry purée and vanilla extract, mixing until combined. If needed, add heavy cream one tablespoon at a time until you achieve the desired consistency. Beat on medium-high speed until light and fluffy, about 3-4 minutes.
11 -
Once the cupcakes are completely cooled, pipe or spread the blackberry frosting onto each cupcake.
12 -
If desired, garnish each cupcake with a fresh blackberry, chocolate shavings, or edible flowers. Serve at room temperature for the best flavor and texture.