Preheat oven to 350 degrees Fahrenheit (175 degrees Celsius).

Mix together flour, baking powder, and salt in a small bowl. Beat together the margarine or oil and sugar until light and fluffy, scraping down the bowl if necessary. Add yolks and vanilla. At low speed, beat in flour mixture until combined.

Press down into a nine- x 13-inch (23- x 33-centimeter) baking pan lined with Gefen Parchment Paper. (Flour your hands if necessary.) Bake for 10 minutes. Cool.

Pour coffee liqueur into a small bowl. Brush it carefully all over the cake base. Allow it to sit a few minutes until liqueur is “dry” and slightly absorbed. (If the hot chocolate touches the liqueur, the chocolate will seize and not be smooth.)

Smear the melted chocolate on top.

Beat egg whites at high speed until foamy. Gradually add sugar, coffee, and cocoa, beating until stiff but not dry peaks form.

Spread topping evenly over chocolate to the sides of the pan; smooth top.

Bake for 15 minutes or until lightly browned. If topping gets brown too fast, cover the pan loosely with a piece of parchment paper. Remove from oven. Cool slightly. Cut into squares.