Preheat oven to 375 degrees. Cream butter and sugar together until fluffy. Beat in egg and peppermint extract. In a separate bowl combine flour, cocoa powder, salt, and baking soda; then gradually mix into creamed mixture. Drop tablespoonfuls onto a greased baking sheet, bake 10-12 minutes until tops are cracked. Next, liquify the marshmallow creme by place 4 heaping teaspoons of creme and 3 tablespoons of water in a microwave safe bowl. Microwave on high for 15 seconds. Remove, stir, and drizzle the marshmallow creme across each cookie. Sprinkle each cookie with crushed peppermint.
