Filling

1 package (8 ounces) cream cheese, at room temperature
1 cup cold mascarpone cheese
1 cup powdered sugar
1 generous teaspoon vanilla extract
1/4 teaspoon allspice
1/2 teaspoon cinnamon
1/4 teaspoon nutmeg
1/8 teaspoon salt
1/2 cup coarsely chopped toasted pecans
1/2 cup whipping cream

Using a mixer fitted with a paddle attachment, beat cream cheese on medium speed until creamy. Add mascarpone and beat until incorporated. Add powdered sugar, vanilla, allspice, cinnamon, nutmeg, and salt; beat on medium-high speed until combined, about 1 minute. Stir in pecans. In a separate large bowl, using a mixer, whip cream on high speed until soft peaks form, 1 to 2 minutes. Fold whipped cream gently into cream cheese–pecan mixture.

Cake

4 large eggs, separated
1/4 cup firmly packed light-brown sugar
1/2 cup all-purpose flour
1 teaspoon baking powder
1 teaspoon baking soda
1/2 teaspoon salt
1/2 teaspoon cinnamon
1/2 teaspoon allspice
1/2 cup canned pumpkin (not pumpkin pie filling)
1/4 cup sugar

Preheat oven to 350 degrees. Line bottom and one short side of a rectangular baking pan (approximately 12 by 17 inches) with parchment paper, leaving several inches hanging over short side. Coat paper and sides of pan lightly with cooking spray.

Using a mixer fitted with a whisk attachment, beat egg yolks in a large bowl on medium-high speed until thick and frothy, about 2 minutes. Add brown sugar and mix on medium speed for 1 minute longer. In a separate bowl, stir together flour, baking powder, baking soda, salt, and spices. Add dry ingredients to egg yolk mixture a third at a time, beating on medium speed after each addition. Add pumpkin and mix on low speed until combined.

Pour egg whites into a large clean bowl. Using a mixer fitted with a whisk attachment, whip on high speed until soft peaks form, 1 to 2 minutes. Add sugar 1 tablespoon at a time, beating on high speed after each addition. Fold egg whites gently into batter. Spoon batter evenly into pan and smooth it carefully; it will not even out as cake bakes. Bake until cake is golden brown and springs back when touched lightly, 15 to 20 minutes. Let cool for 15 to 20 minutes, but no longer, then remove from pan without peeling off parchment paper (use paper as a handle to gently slide cake out). Cake should be rolled while still warm or it will break, so immediately top it with filling and then—starting with short end closest to you—roll it up, peeling away parchment paper as you go. When cake is completely rolled up, carefully transfer to a rectangular serving plate.

Garnish

2 ounces dark chocolate
2 ounces white chocolate
1 cup whipping cream
1/4 cup powdered sugar, plus some for dusting
1/2 cup toasted walnut halves
Rum-Caramel Sauce

Place dark and white chocolates in separate bowls and melt in a microwave on medium-high for about 45 seconds. If not fully melted, stir and return to microwave for 15 seconds more.

Using separate spoons, drizzle melted chocolates over pumpkin roll in a zigzag pattern. Whip cream with powdered sugar and pipe down center of roll. Top with walnuts and dust with powdered sugar. Slice with a serrated knife, and serve with remaining whipped cream and warm Rum-Caramel Sauce.

Serves 10 to 12.

Rum-Caramel Sauce

1 cup sugar
1/4 cup (1/2 stick) unsalted butter
pinch salt
3/4 cup whipping cream
2 tablespoons dark rum, such as Myers’s

Put sugar in a heavy saucepan or iron skillet and cook over medium heat until it is completely melted and amber in color, about 5 minutes.

Reduce heat to low, add butter and salt all at once, and stir to combine (it will bubble up). Add cream a couple of tablespoons at a time, stirring after each addition. (Adding cream slowly keeps caramel from clumping.) Continue stirring until mixture is melted and smooth. Remove from heat and stir in rum.

Serve pie warm or at room temperature, with Rum-Caramel Sauce on the side or drizzled over each slice.