Orange Slices
Ingredients
100g butter, softened
120g sugar
3 eggs, separated, +1 egg yolk
Grated peel of 2 oranges
Juice of 1 orange
1 tsp baking powder
100g ground almonds
200g orange marmalade

Frosting:
200g powdered sugar
1/4c orange juice
2 Tbs Grand Marnier

Instructions
Grease and flour 13x9 inch cake pan.
Beat butter, sugar and 4 egg yolks until pale and fluffy. Add orange peel and juice. Beat egg whites separately until very stiff. Fold egg whites into creamed batter. Add flour and almonds. Stir gently. Pour gently into cake pan and bake in preheated 350F oven for 10-15 min.
Cut cooled cake horizontally into 2 layers. Spread with marmalade.
Combine powdered sugar, orange juice and liqueur in a small bowl. Pour frosting over cake. Cut into slices once frosting has set.