Spray a deep dish pie plate with cooking spray. (Or you can use an 8x8 baking pan or round cake pan.)
In a medium bowl, mix together the pumpkin puree, sugar, egg and vanilla. Mix well.
Add the sourdough starter and mix again.
In a separate bowl, whisk together the flour, baking powder, soda, salt and pumpkin pie spice.
Add to the pumpkin mixture and mix.
Add in the melted butter and mix just until combined.
Pour the batter into the prepared pie plate and smooth it until even.
In a small bowl, combine the topping: brown sugar, pumpkin pie spice and pecans. Use a fork to mix it well.
Sprinkle the topping over the cake batter.
Bake for about 25 minutes or until the center of the cake springs back when you lightly touch it.
Store leftovers in an airtight container.
The calories shown are based on the cake being cut into 8 pieces, with 1 serving being 1 slice of cake. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate. **We are not dietitians and recommend you seek a nutritionist for exact nutritional information.**