Preheat oven to 350°F and line or grease a 24-cup muffin tin.
Combine chopped chocolate and cocoa powder in a bowl, then pour in boiling water and stir until smooth.
Mix in sour cream, raspberry extract, and lemon juice; set aside.
In another bowl, whisk flour, baking soda, and salt.
Cream butter and sugar until light and fluffy.
Add eggs one at a time, mixing well after each addition.
Alternately add dry ingredients and chocolate mixture, mixing just until combined.
Fold in crushed raspberries and chocolate chips.
Fill muffin cups halfway and bake for 15 minutes or until a toothpick comes out clean.
Cool in pan 15 minutes, then transfer to a rack to cool completely.
Strain raspberries to extract juice for frosting.
Beat butter, powdered sugar, raspberry juice, and raspberry extract until smooth.
Adjust consistency with milk or more sugar as needed.
Frost cooled cupcakes and garnish as desired.