Beat cream in large mixer bowl until soft peaks form. Gradually beat in 1/4 cup Nesquik until stiff peaks form. Stir in 1 cup Butterfinger pieces.
Spread about 1 heaping teaspoon whipped cream mixture evenly onto each of 6 graham cracker squares; stack. Place stack on side on long platter or baking sheet so graham crackers are vertical. Repeat with remaining graham crackers and whipped cream mixture until 5 stacks are assembled. Press stacks together to form a loaf.
Spread remaining whipped cream mixture over top and sides of graham cracker loaf. Top with remaining Butterfinger pieces.
Refrigerate for at least 2 hours or overnight. To serve, slice diagonally across loaf into 1-inch slices. Place each slice on plate and top with remaining Nesquik.