How to Make It
Heat oven to 325º F. Butter an 8-by-8-inch baking dish and line with parchment, leaving an overhang on two sides; butter the parchment.
Pulse the almonds in a food processor until finely chopped. Add the flour, ¼ cup of the sugar, and ¼ teaspoon of the salt and pulse twice to combine. Add the butter and pulse until the mixture resembles coarse meal. Add the egg yolk and process until the dough comes together.
Press the dough into the bottom of the prepared pan. Bake until the crust is golden brown around the edges, 14 to 18 minutes.
Meanwhile, process the cream cheese in a food processor until smooth, scraping down the sides of the bowl as necessary, 1 to 2 minutes. Add the eggs, lemon zest and juice, and ¾ cup of the sugar and process until smooth, about 30 seconds. Pour the mixture on the hot crust and bake until just set, 30 to 35 minutes.
Combine the sour cream and the remaining 2 tablespoons of the sugar in a small bowl. Spread over the hot cheesecake, then bake until set, 3 to 4 minutes more.
Let cool to room temperature in the pan, then refrigerate for at least 2 hours. Run a knife around the edge of the cheesecake before unmolding. Holding the paper overhang, lift the bars out of the pan and transfer to a cutting board. Cut into 16 squares.
Storage suggestion: Store the bars in the pan and refrigerate for up to 2 days in advance. Cut just before serving.