Step 1

Preheat oven to 300°F (149°C). Line the bottom and sides of an 8 or 9-inch square baking pan with aluminum foil or parchment, leaving an overhang on all sides to easily lift the bars out of the pan before cutting. Set aside.

Step 2

Mix the graham cracker crumbs and melted butter together in a medium bowl until combined. Evenly press crust into the prepared baking pan. Bake for 8 minutes. Remove from the oven and set aside.

Step 3

In a large bowl using a handheld or stand mixer fitted with a whisk attachment, beat the cream cheese on high speed until completely smooth, about 1 minute. On medium-high speed, beat in yogurt until completely combined. Then beat in the eggs and egg yolk until combined. Finally, beat in the sugar, lemon juice, lemon zest, and vanilla extract until everything is combined and no lumps remain.

Step 4

Pour filling onto the crust. Bake for 28-32 minutes or until the center of the bars no longer jiggles (remove from the oven and gently wiggle the pan to check). Allow the bars to cool at room temperature set on a wire rack for 30 minutes, then transfer to the refrigerator to chill for 3-4 hours or even overnight.

Step 5

Once chilled, lift the foil out of the pan using the overhang on the sides and cut into squares. For neat squares, I use a very sharp knife and wipe it clean with a paper towel after each cut. Leftovers keep well in the refrigerator for up to 5 days.