Preheat oven to 350 F. Grease and line a 9 inch round cake pan with parchment paper.
In a large bowl, add the eggs, sugar, vanilla extract, and whisk to combine.
Now add the oil, yogurt, pumpkin puree, pumpkin pie spice and whisk everything until combined and lump free.
Sift the flour, baking powder, baking soda, and stir until just combined. Make sure to not overmix the batter.
Pour the batter into the greased and lined cake pan.
Make the Crumble Topping :In medium size bowl, add the flour, light brown sugar, granulated sugar, cinnamon, salt and whisk until combined. Add the cold cubed unsalted butter. Rub the butter into the flour and sugar mixture with your clean fingers. You want to combine until the butter is throughout all the flour/sugar. The texture should resemble a crumbly, wet sand consistency . Add the pumpkin seeds and mix with a fork to combine. Evenly distribute the crumble topping over the cake.
Place the cake in the oven on the midd rack and bake for about 40-43 minutes or until the center is set and a toothpick inserted in the center comes out clean or with a few moist crumbs, but no batter.
Allow the cake to cool for about 10 minutes before inverting onto a cooling rack and allowing it to cool completely before cutting into.
You can top the cake with powdered sugar or a cinnamon glaze.
