For the sponge: combine flour with dry ingredients. Mix margarine, vanilla, sugar and egg replacer then add to flour and mix. Spread on a sheet pan and bake at 180C/350F for 35 minutes. Cool.
Mix whipped topping with liquor and set aside.
When sheet cake is cool, cut into "fingers" and dip in strong coffee and lay in bottom of tiramisu bowl. Top with sliced fruit and spread on whipped topping. Put another layer of coffee dipped fingers over topping, layer on fruit, then more topping. Make another layer and end with whipped topping. Sprinkle on bittersweet chocolate shavings or chocolate powder (optional) and garnish with a few pieces of sliced strawberry. Refrigerate tiramisu for several hours before serving.