Preheat oven to 350 degrees F. Spray a 9 x 13 inch baking dish with baking spray, or grease the pan with butter and flour.
In a large bowl sift together flour, baking powder, and salt. Separate eggs yolks from egg whites.
In a separate bowl, beat egg yolks with 3/4 cup sugar on high speed until the color is a pale yellow. Stir in milk and pumpkin emulsifier. Pour egg yolk mixture over the flour mixture and stir until just combined.
Beat egg whites on high speed until soft peaks form. Then add in remaining 1/4 cup sugar and beat until egg whites are stiff.
Gently fold egg white mixture into the batter until just combined. Pour batter evenly into prepared pan. Spread batter with a spatula to even it out.
Bake for 35 to 45 minutes or until a toothpick comes out clean. Invert cake out onto a platter and let cool.
Combine condensed milk, evaporated milk, pumpkin, pumpkin pie spice and heavy cream in a bowl. When cake is cool, pierce the surface numerous times with a fork. Slowly pour the pumpkin cream mixture over the cake.
Allow the cake to absorb the milk mixture for at least 30 minutes. I recommend covering the cake and refrigerating overnight.
For the amaretto whipped topping, whip 1 pint heavy cream with 1/8th teaspoon amaretto flavored oil and 3 tablespoons of powdered sugar until it is thick and spreadable.
Spread the whipped topping evenly over the cake. Sprinkle with cinnamon. Cut into squares and serve.