Cream 1/2 cup butter and gradually add 1 cup sugar, creaming well. Add egg, milk, vanilla and salt. Stir in flour and almonds. Turn into 8x8 baking pan, greased on bottom. Bake for 30 to 35 minutes at 350 degrees.
Remove from pan. Cool. Cut in half horizontally with sharp knife to make 2 thin layers. Spread bottom layer with Butter Filling and then Raspberry Filling. Top with second layer and then with Whipped Cream Topping. Chill at least 4 hours.
Raspberry Filling: Combine 1/4 cup sugar, cornstarch and raspberries in sauce pan. Cook, stirring constantly, until thick. Cool completely.
Butter Filling: Cream 1/2 cup butter and gradually add confectioner's sugar, creaming well. Add egg and beat until fluffy.
Whipped Cream Topping: Beat whipping cream until thick. Stir in 3 tablespoons sugar and walnuts. Continue beating until stiff.
Garnish with extra fresh raspberries and mint leaves.