Topping

1. In a small bowl, combine the topping ingredients. Set aside.

Cake

1. Preheat the oven to 375 F. Spray an 8X8 square baking pan with non-stick spray and set aside.
2. In a large bowl, with an electric mixer, beat eggs with sugar on high speed until light in color and thick.
3. Add sour cream, avocado oil, and vanilla. Beat on low speed until well combined.
4. In a separate bowl, whisk together the flour, baking powder, and salt. Add flour mixture to the batter in thirds, beating after each addition. Scrape down the sides as needed. The batter will be thick. Do not overmix.
5. Pour half the batter into the baking pan. Layer with half of the diced apples and then half of the topping. Pour the remaining batter, layer with the rest of the apples, and topping.
6. Bake for 45-55 minutes or until a toothpick inserted into the middle comes out clean.