Prep: Let eggs stand at room temperature for 30 minutes. Preheat oven to 375 degrees F. Lightly grease a 15 x 10 baking pan. Line bottom of the pan with waxed paper; grease the paper. Set pan aside.

For the cake:

1. In a small bowl, stir together flour, cinnamon, baking powder, ginger, salt, pumpkin spice, and nutmeg; set aside.
2. In a large mixing bowl, beat eggs with an electric mixer on high speed about 5 minutes or until thick and lemon color. Gradually add sugar, beating on medium speed until light and fluffy.
3. Stir in pumpkin puree and lemon juice. Add flour mixture; beat on low speed just until combined.
4. Pour batter into the prepared pan, spreading evenly. Sprinkle evenly with nuts.
5. Bake for 15 minutes or until cake springs back when lightly touched.
6. Immediately loosen edges of cake from pan and turn the cake out onto a towel sprinkled with powdered sugar. Remove waxed paper. Cool completely - around an hour. Then, cut cake width-wise into thirds.

Coffee Syrup:

1. In a small saucepan combine sugar, water, and coffee powder. Bring to a boil over medium heat, stirring to dissolve sugar. Boil gently for 1 minute. Remove from heat. Stir in amaretto and hazelnut liqueur.

Coffee-Maple Mascarpone Cream:

1. In a large mixing bowl, beat whipping cream, powder sugar, mascarpone cheese, and coffee-infused Vermont Maple Syrup with an electric mixer on medium to high speed until soft peaks form (tips curl).

To assemble:

1. Place one of the cake layers, nut side up, on a serving plate (if any of the nuts fall off when inverting cake layers, sprinkle them over the cake layers when assembling).
2. Drizzle one-third of the Coffee Syrup over cake layer. Then, spread evenly with 3/4 cup Maple Mascarpone Cream. Repeat for second layer.
3. Top with remaining cake layer and drizzle with remaining Coffee Syrup. Frost top and sides of cake with remaining Mascarpone Cream.
4. Cover and chill cake for 2 to 24 hours.
5. If desired, garnish top of cake with additional chopped hazelnuts and shaves of bittersweet chocolate.