1. Place a rack in the lower third of the oven and preheat to 350 degrees.
Line a 12 cup muffin pan with baking liners. Using a electric mixer, beat the cream cheese and confections' sugar for 3 minutes. Beat in 1 egg white and 1/2 teaspoon vanilla.
2. In a bowl whisk the flour, pumpkin pie spice, baking powder and 1/2 teaspoon salt. In another bowl, mix the pumpkin puree, 2 eggs, granulated sugar, oil and 1 teaspoon vanilla. Whisk in the flour mixture.
3. Layer each muffin cup with some of the pumpkin bater, then the cream cheese batter mixture, the more pumpkin batter. Bake until springy to the touch 25 minutes minutes. Let cool.
4 Using the electric mixer, beat the brown sugar, remaing 4 egg white and remaing 1/4 teaspoon of salt. Fill a medium sauce pan with enough simmering water to reach the depth of 1 inch; place the mixing bowl on top. Whisk the mixture until it registers 160 degrees on an instant read thermometer.
5. Transfer the bowl back to the mixer and beat on high speed until fluffy; lower the speed and beat to room temperature about 5 minutes. Add the butter, 1 tablespoon at a time, then beat in the remaining 1/2 teaspoon vanilla.
6. Transfer the frosting to a pastry bag, pipe large rosettes on the topp of the cupcakes.