01 -
Turn the oven on and set it to 350°F (175°C). Put paper liners in the cups of a 12-slot cupcake pan.
02 -
In a medium mixing bowl, stir together the baking soda, salt, flour, and cocoa powder until it's all evenly combined. Put it aside.
03 -
Using a large bowl, stir the melted butter and brown sugar until smooth. Beat in one egg at a time, making sure each one is fully mixed before moving on to the next. Toss in the vanilla, buttermilk, and the mashed blackberries, then stir until everything looks blended.
04 -
Little by little, add the dry mix into the wet mix. Gently fold it together, and don’t overdo it—just until it’s mixed.
05 -
Slowly stir in the warm coffee or hot water until your batter has a smooth, runny consistency (this is what you want!).
06 -
Pour the batter into the cupcake liners, filling them roughly three-fourths of the way to the top.
07 -
Place the pan in the preheated oven and let these cook for 18 to 22 minutes. They're done when a toothpick comes out clean or with just a crumb or two.
08 -
Once baked, let cupcakes rest in the pan for five minutes. Then transfer them to a wire rack to cool fully before frosting.
09 -
As the cupcakes cool, blend fresh blackberries into a smooth purée. Use a fine sieve to strain the mix, leaving you with smooth purée and no seeds.
10 -
In a big bowl, use a mixer to beat the softened butter until it’s creamy (about 2 minutes). Gradually stir in the powdered sugar to combine. Add the blackberry purée and vanilla next, then mix. For a good consistency, stir in a tablespoon or two of heavy cream. Whip on medium-high for 3-4 minutes until the frosting is fluffy.
11 -
Once the cupcakes have fully cooled, use a spoon or piping bag to frost them with your blackberry frosting.
12 -
If you’d like, add a few fresh blackberries, bits of chocolate, or flowers on top. Serve at room temperature for the best texture and flavor.