Beat 3/4 cup butter at medium speed with an electric mixer until creamy. Gradually add 1 cup sugar, beating well. Add eggs, 1 at a time, beating until blended after each addition.
Combine 2 cups flour, baking powder, baking soda, and 1/4 teaspoon salt; add to butter mixture alternately with sour cream, beginning and ending with flour mixture. Beat at low speed until blended after each addition. Stir in coconut extract and 1/2 teaspoon almond extract.
Spoon half of batter into a greased 9" square pan. Combine flaked coconut, sweetened condensed milk, remaining 1/4 teaspoon salt, and remaining 1/4 teaspoon almond extract; stir well. Spread over batter in pan. Spread remaining batter over coconut mixture.
Combine 1/3 cup flour, 1/4 cup sugar, and almonds. Cut 1/4 cup butter into flour mixture with a pastry blender until crumbly. Sprinkle mixture over batter. Bake at 350° for 30 to 35 minutes or until a wooden pick inserted in center comes out clean. Cool in pan on a wire rack.