Take your pumpkin spice cake to the next level with this pretty, party-worthy presentation.
Preheat oven to 375 degrees. Butter a rimmed baking sheet and line with parchment, leaving a slight overhang on short ends. Butter parchment and dust with flour.
Whisk flour, ginger, cinnamon, nutmeg, baking soda, baking powder and salt in a medium bowl until thoroughly combined. Set aside. Lay a clean kitchen towel on a flat surface and dust with 1/4 cup confectioners' sugar.
In the bowl of an electric mixer fitted with paddle attachment, cream eggs and sugar on medium-high speed until pale and fluffy and tripled in volume, about 10 minutes. Reduce speed to low and add pumpkin puree. Mix until combined, about 2 minutes. Turn mixer off and sift half of flour mixture over the top. Gently fold into the batter than repeat with remaining dry mixture. Spread evenly onto prepared baking sheet with an offset spatula and bake until the cake springs back in the center and begins to pull away from edges, about 12 minutes. Let cool 10 minutes then invert onto sugar-dusted towel. Fold the sides of the towel over the cake and gently roll the cake lengthwise. Let cool completely, about 20 minutes.
In a small saucepan, bring cream just to a simmer. Pour over white chocolate set in a small bowl, making sure chocolate is fully covered. Let sit 5 minutes. Stir until smooth. In a medium bowl stir mascarpone with a rubber spatula until smooth. Add half the ganache and stir to combine. Repeat with remaining half, then whisk and continue to whip until just beginning to hold soft peaks and the mixture is spreadable. Stir in orange zest. Unroll pumpkin cake and evenly spread 2 cups of filling over the top, leaving a 1/2-inch border on long sides. Gently roll again and place in refrigerator to chill, 15 to 20 minutes. Dust with confectioners' sugar, slice and serve.