Yield: 12 cupcakes
2 oz unsweetened chocolate, chopped
¾ cup + 2 Tbsp (124g) all-purpose flour
¼ cup + 2 Tbsp (38g) unsweetened cocoa powder
¾ tsp baking soda
¼ tsp salt
1 cup (220g) granulated sugar
¼ cup (56g) unsalted butter, softened
1 large egg
1 large egg yolk
1 ½ tsp vanilla extract
½ cup (124g) sour cream
½ cup boiling water
Raspberry Buttercream Frosting
12 or 24 raspberries (12 if you only want to add to tops, 24 if you want one underneath frosting too)
Preheat oven to 350 degrees. Line a 12-cup muffin tin with cupcake liners. Melt chocolate in a microwave safe bowl on 50% power in 20 second intervals, stirring between intervals until melted and smooth, set aside to cool slightly. In a mixing bowl whisk together flour, cocoa powder, baking soda and salt for 20 seconds, set aside.
In a large mixing bowl using an electric hand mixer mix together sugar and butter until combined (it won’t come together entirely but mix until lumps of butter are creamed), mix in egg, egg yolk and vanilla extract. Mix in melted chocolate then mix in sour cream. Add half of the flour mixture and mix on low speed until combined then add remaining half and mix until combined. Add about 1/5 of the boiling water at a time, mixing until combined after each addition. Once water has all been mixed in mix batter on medium-low speed for 1 minute.
Divide batter among prepared muffin cups, filling each about 2/3 full (it’s about ¼ cup of batter). Bake in preheated oven until set and toothpick inserted into center comes out clean, about 17 — 20 minutes. Remove from oven, transfer to a wire rack and cool 10 minutes, then transfer to an airtight container (one that doesn’t touch tops. I like to do this to seal in moisture) and allow to cool completely before frosting. Once cool frost with Raspberry Buttercream Frosting and top with raspberries. Store in an airtight container in refrigerator.
If you’d like to make the chocolate hearts for decoration, I simply melted about 2 ounces of dark chocolate in the microwave on 50% power in 20 second increments, stirring between intervals until melted and smooth. Let it cool slightly then transfer to a piping bag fitted with a small plain round tip. Over a baking sheet lined with waxed paper, pipe heart shapes with a small stick on the end (which will poke down into the frosting and hold it up). Let set in refrigerator until firm then gently peel from parchment while chocolate is still cold.