Prep. Preheat oven to 375 F, and prepare a muffin pan with liners.
Topping. Add topping ingredients to a small bowl and mix to combine. Set bowl aside.
Dry ingredients. In a medium bowl, combine the almond flour (2 cups), coconut flour (1/2 cup), erythritol (3/4 cup), baking powder (1 1/2 teaspoon), salt ( 1/2 teaspoon), pumpkin pie spice (2 teaspoons), and stir to combine.
Wet ingredients. In a large bowl combine eggs (4), pumpkin puree (3/4 cup), unsalted butter ( 1/4 cup), vanilla (2 teaspoons), and combine using an electric mixer. Add dry ingredients to wet ingredients and combine.
Assemble + bake. Pour batter into the prepared muffin pan, and use your fingers to smooth out the top of each muffin. Divide the crumble topping over the muffins, and press lightly to adhere. Cook for 22 minutes. Check, and if the tops of your muffins are browning, add foil. Cook for an additional 3-5 minutes, or until a toothpick inserted in the center comes out clean.