Preheat your oven to 350°F. Grease an 8×8-inch baking pan or line it with parchment paper for easy removal.

To make the topping, combine almond flour, coconut sugar, pecans, cinnamon, and coconut oil in a small bowl. Use a fork to mix until crumbly, then set aside.

In a medium mixing bowl, whisk together almond flour, oat flour, salt, cinnamon, and baking soda.

In a large bowl, beat the eggs. Add Greek yogurt, melted coconut oil, vanilla extract, and maple syrup, whisking until smooth.

Gradually add the dry ingredients to the wet ingredients, stirring until just combined. Avoid overmixing.

Gently fold in the chopped apples, ensuring even distribution throughout the batter.

Pour the batter into the prepared pan and evenly sprinkle the crumb topping over the surface.

Bake in the preheated oven for 40-50 minutes. The cake is ready when a toothpick inserted into the center comes out clean or with only a few moist crumbs.

Check the topping at the 30-minute mark. If it’s browning too quickly, tent the cake with foil for the remaining bake time.

Let the cake cool in the pan for about 15-20 minutes. Then transfer it to a wire rack to cool completely before slicing into squares.