Make the crumble: Mix the crumble ingredients together, using a fork or your fingers to push the oil/butter into the flour sugar. Place in the fridge.
Preheat the oven to 350 F.
In a large bowl, mix together the oat flour, almond flour, baking soda, baking powder, pumpkin spice and salt.
In a separate bowl mix the pumpkin, eggs, maple syrup, oil and vanilla until smooth.
Pour the wet ingredients into the dry ingredients and gently mix.
Pour the batter into a parchment lined 8 x 8 baking dish.
Sprinkle with the crumb topping.
Bake for about 30-35 minutes, until the top is firm to touch and a toothpick comes out clean.
Let cool completely before slicing.
