- 1 ¾ cups all-purpose flour, divided
- ⅔ cup brown sugar
- 1 tablespoon cinnamon
- ¼ + a pinch of salt, divided
- ½ cup + 6 tablespoons unsalted butter, melted, divided
- 1 cup blanched almond flour
- ⅓ cup granulated sugar
- 1 teaspoon baking soda
- ¾ cup unsweetened applesauce
- 2 large eggs
- 2 tablespoons maple syrup
- 1 teaspoon vanilla extract
- Preheat the oven to 350 F and grease a square baking dish (either 8x8- or 9x9-inch).
- Make the streusel by combining 1 cup all-purpose flour, the brown sugar, cinnamon, and a pinch of salt. Stir or whisk to combine. Add 6 tablespoons melted butter and stir until a wet crumble forms.
- Make the cake batter by combining the remaining ¾ cup all-purpose flour, almond flour, granulated sugar, baking soda, and remaining ¼ teaspoon salt in a medium bowl. Whisk to combine. Set the dry ingredients aside.
- Mix the wet ingredients by adding the applesauce, remaining melted butter, eggs, maple syrup, and vanilla to the bowl of a mixer. Mix until blended, about 1 minute.
- Add the dry ingredients to the wet ingredients and stir until just combined.
- Pour half the cake batter into the prepared baking dish. Top with half the streusel mixture, spreading it to cover the batter. Repeat with the remaining batter and streusel mixture.
- Bake the coffee cake in the preheated oven for 35-40 minutes, until the top is golden crisp and a toothpick inserted into the center comes out clean.