1¾ cups well-chilled heavy whipping cream¼ cup sugar½ to ¾ teaspoon mint extract1 package (9 ounces) chocolate wafers1¼ cups miniature chocolate chipsMint leaves for garnishIn a large mixing bowl, beat the heavy cream, sugar and mint extract until stiff peaks form.To assemble the cake: Spread each wafer with about 1 tablespoon of mint cream, forming about four stacks of six to eight cookies. Lay the stacks side by side on a sheet of wax paper, pressing gently to form a log. With small spatula or knife, cover log with remaining mint cream. Refrigerate at least 6 hours or up to 2 days.To serve, gently remove wax paper from underneath cake (holding cake in place with a metal spatula, if necessary), and sprinkle with chocolate chips. Slice cake diagonally with a serrated knife into 1-inch-thick slices.Note: It's best to allow this cake to set overnight.