• Preheat the oven to 350 F and line a 9 x 13 inch baking pan with aluminum foil, leaving an overhang to help lift the bars out.
• In a large bowl, mix together the cream cheese and butter until smooth. Add the sugar, and cream together with an electric mixer, 2-3 minutes. Mix in the vanilla extract and egg.
• Combine the flour, baking powder and salt in another bowl and stir into the butter mixture until well combined.
• Press the dough evenly into the prepared pan and bake for 25-30 minutes, until just lightly browned on top. Transfer the pan to a wire rack and cool completely.
• Remove the bars from the pan using the foil overhang.
• Frost the bars with the buttercream and sprinkle with red and green sprinkles. Cut and serve.

Frosting

• In a large bowl, beat the butter with an electric mixer until smooth.
• Gradually add the sugar and mix on low speed to combine. Switch to high speed and whip for about 3-4 minutes until fluffy.
• Add the whipped cream, salt and vanilla extract and whip again for 3-4 minutes until very light and fluffy.