Preheat the oven to 350°F. Grease a 9-inch round cake pan with butter and line the bottom with parchment paper.
In a large bowl, whisk together the oil, brown sugar, granulated sugar, eggs, pumpkin, and vanilla until combined.
In a separate bowl, whisk together the flour, baking powder, baking soda, cinnamon, nutmeg, cloves, ginger, and salt.
Add the dry ingredients to the wet ingredients and stir until just combined. Fold in the pecans and walnuts.
Pour the batter into the prepared pan and spread evenly. Bake for 35-40 minutes, or until a toothpick inserted into the center comes out clean.
Allow the cake to cool completely before frosting.
In a medium bowl, beat together the marmalade, cream cheese, butter, and orange zest until combined. Gradually add the confectioners' sugar and beat until light and fluffy.
Spread the frosting over the cooled cake and serve.
Interesting Facts
Pumpkin is a great source of vitamin A, iron, and magnesium.
Orange zest and marmalade adds a delicious citrus flavor to the cake.