Preheat oven to 180 °C (350 °F). Line the bottoms of two 18 -20-cm (8-inch) cake pans with circles of baking paper and then grease them well.
In a bowl combine flour, baking powder, salt, cinnamon, nutmeg and ginger and set aside.
In a large mixing bowl beat eggs and the two kinds of sugar at high speed for about 10 minutes, until the mixture thickens. Add oil and beat for 2 more minutes. Add pumpkin puree and vanilla and beat shortly, until combined.
Using a rubber spatula fold the dry ingredients into the mixture. Continue mixing gently until all the flour is absorbed
Divide the batter between the two prepared pans. Bake for 45 to 50 minutes or until a toothpick inserted in the centre comes out clean. Let the cakes cool for 10 minutes in the pans before removing them. Transfer to a wire rack to cool completely. When the cakes reach room temperature, refrigerate for few hours before cutting them.
In a large bowl beat together mascarpone, powdered sugar, rum extract and pumpkin puree until all ingredients are well combined and the mixture becomes creamy.
In a separate bowl whip the cold cream until very thick.
With a rubber spatula carefully add the whipped cream to the mascarpone mixture. Fold gently until the two are combined.
To assemble and decorate:
With a long serrated knife cut horizontally each cake into 3 equal layers. Place one layer on a cake stand or on a serving plate and cover with some mascarpone frosting. Place another layer on top.
Continue the process until finishing all the layers. Cover the cake all around and on top with the rest of the mascarpone frosting.
Decorate with marzipan pumpkins - see photos below for instructions how to make them.
Instead of self-raising flour you can use all-purpose with additional 3 teaspoons baking powder.