Ricotta-Filled Cake

1 (18 1/4 ounce) box yellow cake mix
3/4 cup granulated sugar
1/4 teaspoon vanilla extract
2 pounds ricotta cheese
1 large can crushed pineapple, drained
4 eggs

Grease a 13 x 9-inch pan.

Mix cake according to directions on box. Pour free cake mix into prepared pan.

Beat eggs. Mix ricotta, sugar, beaten eggs, pineapple and vanilla extract together. Pour filling mixture over cake batter and spread evenly, but DO NOT mix with the batter. Bake at 350 degrees F for 1 hour or until a wooden pick comes out clean. Cool, then cut into small squares. Keep in refrigerator.