Heat oven to 350°F; line sheets with parchment.
Microwave semisweet chips and butter in 30-second intervals, stirring smooth; cool slightly.
Whisk sugar into chocolate.
Whisk in eggs individually, mixing well after each; add vanilla and peppermint.
Separately whisk flour, cocoa, baking powder, and salt.
Fold dry into chocolate just until combined.
Fold in Andes chips and dark chocolate chips.
Drop rounded tablespoons dough 2 inches apart on sheets.
Bake 9-11 minutes until tops crackly and edges set with slightly soft centers.
Cool on sheet 10 minutes to firm; transfer to rack.