Heat the oven to 350°F. Grease 4 round or rectangular glass meal prep containers.
Whisk or blend the 4 eggs, 1.5 cups Greek yogurt, ½ cup pumpkin purée, 1 cup milk, ¼ cup maple syrup, 1.5 cups all-purpose flour, 2 tsp baking powder, 1 tbsp pumpkin pie spice, 1 tsp cinnamon, and ½ tsp salt together until completely uniform, some streaks of flour are fine.
Pour into the prepared container.
For the crumb topping, rub the 2 tbsp cold butter into the ¼ cup flour, 2 tbsp brown sugar, 1 tsp cinnamon, and ¼ tsp salt with your fingers until it looks like coarse crumbs. Scatter over the top, don't press it in.
Bake 30 to 35 minutes, until a knife in the center comes out clean. The edges set before the middle does, so check the center.
Cool before storing or enjoy right away with pepitas or maple syrup.