2 tablespoons all-purpose flour
2 teaspoons baking powder
2 teaspoons baking powder salt
1 teaspoon ground black pepper
1 1/4 cups white sugar
1 (1 ounce) square unsweetened instant chocolate cookie crumbs
Preheat oven to 350 degrees F (175 degrees C). Spread 2 tablespoons flour at a time onto the bottom of a 9x13 inch pan. Leave about 1 tablespoon flour on top. Brush bottom and sides of pan with flour.
Bake in preheated oven for 30 minutes, until bubbly. Cool completely. Melt chocolate cookie crumbs overnight in microwave oven or in a bowl over stove or in bowl in large pan; stir gently until chocolate is melted. Remove from oven and place on whipped-cream stand. Begin edge of pan holding in meringue with spoon to prevent sticking. Begin with filling in bottom of pan. Place left over filling on jelly roll pan.
Spread filling between parchment-lined baking sheet and crust. Cool completely. Place sandwich into greased 13x9-inch pan. Toast over simmering water in microwave for 30 minutes, then remove pan; cool completely. Cover loosely with plastic wrap; use knife attachment to secure plastic wrap around edges and bottom of pan. Bake for 30 minutes, or until center of sliced sandwiches is 1/4 inch from outer edge. Cool completely. Cut into 1 inch squares.