Lightly grease a 9-inch fluted tart pan with removable bottom or a cookie sheet; set aside.
In a medium bowl stir together flour and cocoa powder; set aside. In a large mixing bowl beat butter with an electric mixer on medium to high speed for 30 seconds. Add powdered sugar, vanilla, almond extract, and salt. Beat until combined, scraping sides of bowl occasionally. Add flour mixture and beat until mixture resembles fine crumbs and starts to cling. Form mixture into a ball and knead until smooth.
Pat dough evenly into prepared pan or pat into a 9-inch circle on the prepared cookie sheet. If desired, use your fingers to scallop the edge. Score into 12 wedges and prick each wedge 3 times with fork tines, making sure to go all the way through the dough. Press an almond slice into each wedge about 1/2 inch from the edge.
Bake in a 325 degree F oven about 30 minutes or until top looks dry. Cool in pan on a wire rack for 5 minutes. If using, remove sides of tart pan. Cool completely on wire rack. Cut into wedges. Makes 12 wedges.