Chocolate Chunk Blueberry Cupcakes

Ingredients

• 1 cup all-purpose flour
• 1/2 cup cocoa powder
• 1/2 teaspoon baking soda
• 1/2 teaspoon baking powder
• Pinch of salt
• 1/2 cup unsalted butter, softened to room temperature
• 1 cup sugar
• 2 eggs
• 2 teaspoons vanilla
• 3/4 cup buttermilk
• 1 cup semi-sweet chocolate chunks
• 1 heaping cup blueberries
• 1/2 cup water
• 1/2 cup sugar
• 2 tablespoons cornstarch
• 1/2 tablespoon lemon juice
• 1/2 cup heavy cream
• 3 tablespoons sugar
• 1/2 tablespoon unsalted butter
• dash of salt
• 2 ounces unsweetened chocolate, broken into 1/2 ounce pieces
• 3/4 cup unsalted butter, softened to room temperature