Preheat the oven to 350°. Put the oven rack in the upper middle slot. Line a 13x9" pan with aluminum foil, overlapping the foil, making sure there are 2 or 3 inches lap over the ends to lift out the bars later. Spray the bottom and edges of the foil with cooking spray.

For the Crust: In a medium bowl, stir together the flour, powdered sugar, and salt. Add the melted butter and stir together until flour mixture is evenly moistened. Press the dough firmly down in the bottom of the pan, up to the edges. Prick the dough with a fork so the dough won't puff up, about 20 times.

Bake for about 20 minutes until just the edges are golden brown. Take the pan out and place on a wire rack to cool completely, 20 to 30 minutes.

For the Filling: Mix the softened cream cheese and room temperature butter together in a stand mixer bowl until creamy. On low speed, add the powdered sugar, one cup at a time, to the bowl. Scrape down the sides of the bowl as needed.

Increase the mixer speed to medium-high and mix until light and fluffy, about 2 minutes.

Reduce the speed to low, then add the eggs and yolks, one at a time, and mix until completely incorporated. Add the vanilla and salt and mix until combined, scraping down the bowl as needed.

Increase the speed to medium-high and mix until light and fluffy, about 2 minutes. Spread the filling over the cooled crust. Tape the pan on the counter gently to release any air bubbles.

Bake 30-35 minutes until the top is golden brown and edges have cracked. Center should jiggle slightly when the pan is shaken, so don't over bake. Move the pan to a wire rack and let it cool completely, at least 3 hours.

Use the foil overhang to lift the bars out of the pan. Cut into 12 to 16 pieces (they're pretty rich). Dust lightly with powdered sugar if desired.

Store at room temperature in an airtight container for up to 3 days.