Pumpkin Batter:1. Preheat oven to 325°. 2. Butter a sheet pan. 3. In the bowl of an electric mixer, beat the butter and cream cheese until smooth. 4. Slowly beat in sugar making sure to scrape the sides and bottom of the bowl. 5. Beat in the egg(s) then add pumpkin puree, vanilla, cinnamon and ginger, just until incorporated. 6. Add flour until just combined and set aside.
Chocolate Batter:1. In a heat proof bowl combine the semisweet chocolate chunks and butter. Place bowl over a pot of 1-inch simmering water; allow chocolate and butter to melt and stir to fully combine; set aside. Do not discard water. 2. In the bowl of an electric mixer combine eggs, sugar, vanilla and salt; set the bowl over the pot of simmering water, using a whisk beat until blended and sugar has dissolved and is warm to the touch, about 3 minutes. 3. Remove from heat and place the mixer bowl onto the mixer with the paddle attachment, beat until mixture is thick and fluffy, about 5 minutes on medium speed. 4. Using a large rubber spatula, fold in the melted chocolate until completely combined. 5. Sift the flour over the warm batter and fold in until just combined. 6. Spread the chocolate batter evenly in the prepared pan. Fill a pastry bag with the pumpkin batter (snip the tip leaving a ½” open hole.) Pressing the tip into the batter pipe pumpkin batter in parallel lines through tray. 7. Using a paring knife, swirl the pumpkin batter into the chocolate; don’t overdo it or the swirl pattern will be lost. 8. Bake until set about 18 – 20 minutes. 9. Cool on rack until bars are completely cool.