Ingredients
For the cake
1 (15 1/4 ounce) can crushed pineapple with juice, divided (save ½ cup of juice for the cake batter and ¼ cup for the frosting)
1 1/2 cups butter, softened
3 cups sugar
5 eggs
1/2 cup 7-Up or Sprite soda
3 cups cake flour
1 teaspoon lemon extract
1 teaspoon vanilla extract
2 Tb lemon zest
Sweetened shredded coconut (for coating sides of cake)
For the Pineapple Filling
2 cups sugar
1/4 cup cornstarch
1 cup water
½ cup buttermilk
drained crushed pineapple from the can
juice from ½ lemon
1 Tb lemon zest
For the Cream Cheese Frosting
1/2 cup butter, softened
6 oz cream cheese, softened
3 cups powdered sugar, sifted
1 teaspoon vanilla extract
¼ cup reserved pineapple juice
Instructions
For the cake batter:
Grease three 9" round cake pans
Drain pineapple, reserving 3/4 cup juice (reserving ¼ cup for frosting and ½ for cake batter. Set drained pineapple aside).
Beat butter at medium speed with a mixer until creamy; gradually add sugar, beating well.
Add eggs, one at a time, beating until blended after each addition.
Combine 1/2 cup reserved pineapple juice and 7-Up and then add flour to butter mixture, alternately with juice mixture, beginning and ending with flour.
Beat at low speed until blended after each addition.
Stir in extracts.
Pour 1/3 of batter into each of the prepared cake pans.
Bake at 350 for 30 minutes or until a wooden pick inserted in center comes out clean.
Remove from pans immediately; cool on wire racks.
For the Pineapple Filling.
Stir together sugar and cornstarch in a saucepan.
Stir in pineapple, water, buttermilk, lemon juice and zest.
Cook over low heat, stirring occasionally, 15 minutes or until very thick.
Cool.
When cake is cool, make Cream Cheese Frosting.
For the frosting
Beat butter and cream cheese at medium speed with an electric mixer until blended.
Gradually add powdered sugar, vanilla, and pineapple juice, mixing well.
When cake has cooled, stack cake layers, spreading 3/4 cup Pineapple Filling between each layer and some on top within 1/2" of edges.
Spread Cream Cheese Frosting on all sides of the cake and then cover with shredded coconut.