Preheat the oven, depending on the oven to 200 degrees, with convection to 170 degrees.
Wash and core the pumpkin and grate finely on the vegetable grater. Mix the flour, baking powder, baking soda and spices in a bowl. In a second bowl, mix together the sugar, eggs, oil and the sour cream well. Fold in the pumpkin flesh. Now work the flour quickly under the moist mixture and pour it into the well-greased muffin tin (12 mm tin). Bake for about 25 minutes. As always, the baking time depends on the particular oven.