1 Preheat oven to 400 degrees F (200 degrees C). Grease and flour 2 (9 inch) pans. In the top of a double boiler, heat unsweetened chocolate, stirring occasionally, until chocolate is melted and smooth. Remove from heat and allow to cool to lukewarm.
2 In a large bowl, combine flour, baking powder, baking soda, salt and sugar. Cut in margarine until mixture resembles coarse crumbs. Blend in sour milk and melted unsweetened chocolate. Divide batter into prepared pans.
3 Bake in the preheated oven for 15 to 20 minutes, or until a toothpick inserted into the center of the cake comes out clean. Allow to cool. Sprinkle cakes with orange liqueur.
4 Reserve 8 to 10 strawberries and slice the rest. Place one cake on a serving plate, top with half of the sliced strawberries and half of whipped topping. Cover with second layer, top with remaining strawberries and whipped topping. Garnish with whole strawberries. In the top of a double boiler, heat semisweet chocolate, stirring occasionally, until chocolate is melted and smooth. Drizzle over the strawberries.