Basil Lemon Bars

Instructions

• Preheat the oven to 350F. Drape a sheet of parchment paper across an 8×8-inch pan, with it overhanging on two opposite sides and fitting snuggly along the other sides, like a little hammock. Add lemon zest, basil, and sugar into a food processor and pulse until well blended and the basil is finely chopped. The sugar mixture should be fully green.
• Add the flour, both sugars, salt, and black pepper and pulse until well blended. Add in the stick of butter, cut into slices and pulse until the butter pieces are no larger than the size of a pea.
• Remove the dough from the food processor and use your hands to bring it together into a ball. Working quickly, pat the dough evenly into the bottom of the baking dish. If the dough is getting a bit warm, freeze for about 5 minutes (if using a glass dish, carefully remove the parchment and crust once the crust is packed in and freeze for 5 minutes, then return it to the glass dish to bake). Prick the bottom of the crust with the tines of a fork in a few places and then bake for 24-30 minutes, until golden brown.
• Meanwhile, assemble the filling. In a thick-bottomed, non-reactive saucepan (i.e. stainless steel), add the sugar and lemon zest. Massage the lemon zest into the sugar using your hands until the sugar is fragrant and slightly moistened, resembling sand.
• Whisk in the all-purpose flour, cream of tartar, and salt until blended. Whisk in the eggs and egg yolks, and once well-combined, gradually whisk in the lemon juice.
• Cook the mixture over medium to medium-low heat, stirring constantly using a rubber spatula or wooden spoon until the curd begins to thicken, about 7-8 minutes. You will know it’s ready when it coats the back of the spoon and when you run your finger across the back of the spoon, it leaves a clear path.
• Immediately remove from the heat and stir in the 4 Tbsp of butter, cut into smaller slices until they are fully melted. Strain the mixture into a bowl and pour over the cooked crust. Return to the oven and bake for about 10-12 minutes. The lemon bars will be ready when they no longer jiggle in the pan, and the sides will have slightly begun to puff indicating they have just set.
• Let cool at room temperature for about 2 hours before removing from the pan and slicing into squares. To get clean slices, rinse and wipe your knife between slices. If you like a less tart lemon bar, you can sift powdered sugar over the top right before serving or top with fresh or candied basil leaves (see below for details).
• You can serve at room temperature the day these are made, or refrigerate them in an airtight container for several days (I personally prefer my lemon bars chilled and find them to be sturdier when cold). These can also be frozen in a single layer and then stored.
• (Optional): To candy basil leaves, place them on a baking sheet lined with parchment paper. Using a pastry brush or a small, clean paintbrush, lightly and completely brush the front and back of each leaf with egg white. You want them fully coated with only a thin layer. Then either sprinkle sugar on top or drop them into a shallow bowl of sugar and press down on both sides until they are fully coated. Let sit in a dry place in your home for 12-24 hours until they are fully dried and crisp. The time will depend on how humid it is.