01 -
Turn your oven to 350°F (175°C). Line a 12-cup muffin tin with paper liners for the cupcakes.
02 -
Whisk flour, cocoa powder, salt, and baking soda in a medium container until it's all blended. Leave it aside for now.
03 -
Use a big bowl to whisk the melted butter with brown sugar until smooth. Crack in the eggs one at a time, beating well between each. Now toss in the vanilla, buttermilk, and mashed blackberries and mix until it comes together.
04 -
Little by little, stir the dry ingredients into the wet mixture. Be gentle and stop once it’s just mixed to avoid overdoing it.
05 -
Pour in the hot coffee or hot water slowly and mix until the batter evens out. Expect it to be runny—totally normal here.
06 -
Spoon the batter evenly into each cupcake liner, aiming to fill them about ¾ of the way full.
07 -
Slide the tin into the already hot oven and bake for 18-22 minutes. You’ll know they’re ready when a toothpick poked in the middle comes out clean or with just slightly wet crumbs.
08 -
Take the pan out of the oven and leave it for 5 minutes. After that, carefully move the cupcakes to a wire rack to let them cool down fully before frosting.
09 -
As the cupcakes cool, make the purée for your frosting. Blend fresh blackberries in a blender or food processor until smooth. Strain it through a fine sieve to get rid of the seeds, pushing it with a spoon to extract all the liquid.
10 -
Grab a large bowl and use a mixer to beat softened butter until it’s creamy and smooth—this should take about 2 minutes. Slowly stir in powdered sugar on a low speed. Stir in the vanilla and strained blackberry purée. If the texture’s off, add heavy cream a little at a time. Beat on medium-high until it’s fluffy and light (roughly 3-4 minutes).
11 -
Spread or pipe your fluffy blackberry frosting onto the cupcakes after they’ve completely cooled.
12 -
Top your frosted cupcakes with a fresh blackberry, chocolate shavings, or pretty edible flowers if you’d like. These taste best when served at room temperature.