1. Preheat oven to 350°.

2. Butter or grease a 9 X 13-inch baking dish.

To make the crumb topping

1. In a medium bowl, combine the almond flour, all-purpose flour, sugar, and salt.
   

2. Stir together the melted butter, the almond extract, and the vanilla.
   

3. Pour the melted butter mixture into the almond flour mixture. Stir until thoroughly combined, set aside. 
   

To make the coffeecake base

1. In the bowl of a mixer (or you can use a mixing bowl and beat by hand) cream the softened butter and the sugar until very light and creamy.This should take several minutes.
   

2. Add the eggs one at a time, beating well between additions and scraping down the sides of the bowl.
   

3. Beat in the sour cream and the vanilla, scraping down the sides of the bowl again. 
   

4. With a spatula, stir in the flour mixture, blending well, but be careful not to over mix. 
   

To assemble the coffeecake

1. Spread the coffeecake base evenly over the bottom of the prepared baking pan. 
   

2. Using your hands crumble the crumb mixture and evenly distribute the crumbs over the coffeecake base. 
   

3. Sprinkle the sliced almonds over the crumb mixture. 
   

4. Bake for 40-45 minutes, check with a cake tester or toothpick to see if the cake base is done, the tester should barely come out clean with a few crumbs still sticking.
   

5. Turn the broiler on and broil for 2-3 minutes until the almonds are a deep golden brown and the crumb has started to turn a nice golden color.. Be careful and keep an eye on it, the coffeecake can burn easily.