01 - Preheat oven to 350°F. Line a 12-cup muffin tin with paper liners.
02 - Combine chopped dark chocolate and heavy cream in a microwave-safe bowl. Microwave in 20-second intervals, stirring until completely smooth. Cool slightly, then spoon into 12 small mounds (approximately 1 tsp each) on a parchment-lined baking sheet. Freeze for a minimum of 15 minutes until firm.
03 - Sift together flour, cocoa powder, baking powder, baking soda, and salt in a medium bowl.
04 - Whisk melted butter and granulated sugar in a large bowl until well blended. Add eggs one at a time, whisking thoroughly after each addition. Stir in vanilla extract.
05 - Add half of the dry ingredients to the wet mixture, followed by buttermilk, then remaining dry ingredients. Mix gently until just combined—do not overmix.
06 - Place 1 heaping tablespoon of batter into each cupcake liner. Position a frozen chocolate mound in the center, pressing lightly into the batter. Add 2–3 raspberries per cupcake, then cover with remaining batter, filling liners approximately 3/4 full.
07 - Bake for 14–16 minutes until tops are set but centers remain slightly soft to the touch.
08 - Let cupcakes cool in the pan for 5 minutes, then transfer to a wire rack. Dust generously with powdered sugar and decorate with fresh raspberries and chocolate shavings if desired. Serve warm for optimal molten center effect.