01 - Preheat oven to 350°F. Line a 12-cup muffin tin with paper liners.
02 - Place chopped dark chocolate and heavy cream in a microwave-safe bowl. Microwave in 20-second intervals, stirring until smooth and glossy. Cool slightly, then spoon into 12 small mounds (approximately 1 teaspoon each) onto a parchment-lined baking sheet. Freeze for a minimum of 15 minutes until firm.
03 - Sift flour, cocoa powder, baking powder, baking soda, and salt into a medium mixing bowl. Whisk to ensure even distribution.
04 - In a large bowl, whisk melted butter and granulated sugar until well combined. Add eggs one at a time, whisking thoroughly after each addition. Stir in vanilla extract.
05 - Add half of the dry ingredient mixture to the wet ingredients, folding gently. Pour in buttermilk and mix briefly. Add remaining dry ingredients and stir 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 batter. Arrange 2-3 raspberries around each chocolate portion. Top with remaining batter, filling liners approximately 3/4 full.
07 - Bake for 14-16 minutes until tops appear set and a toothpick inserted near the edge comes out clean, while centers remain slightly soft to the touch.
08 - Allow cupcakes to rest in the pan for 5 minutes before transferring to a wire cooling rack. Dust generously with powdered sugar. Top with fresh raspberries and chocolate shavings if desired. Serve warm for optimal molten center effect.