Peppermint Patty Brownie Cupcakes

semi-sweet or bittersweet chocolate, coarsely chopped (I used semi-sweet)

unsalted butter, cut into pieces, at room temperature

white granulated sugar

salt

large eggs, at room temperature

all-purpose flour

unsweetened Dutch process cocoa powder, sifted

small (1 ½-inch) chocolate-covered peppermint patties, such as York Peppermint Patties (I used the "fun size" ones)