Lemon Blueberry Shortbread Bars are bursting with luscious lemon curd and juicy blueberries. This recipe will be the star of all of your summer parties. A word of warning: You will want to eat each and every melt-in-your-mouth-AND-in-your-hands bar all by yourself!
In a large bowl, beat together butter, sugar, and powered sugar. Add vanilla, salt, and lemon zest and beat until well-combined. Mix in flour to form a soft dough. Press 2/3 of the dough evenly into the bottom of the prepared pan to form a crust. Reserve the other 1/3 portion of dough in the refrigerator. Bake 15-18 minutes while you prepare the filling.
In a medium saucepan whisk together egg yolks, whole egg, and sugar until combined. Add lemon juice and salt and whisk until well combined, about 30 seconds. Place over medium-low heat and add butter. Cook, stirring constantly, until the curd thickens, about 6 minutes. Once thickened, stir in Greek yogurt. Fold in 1 cup blueberries, then pour the curd into the warm crust, spreading evenly.
Sprinkle the bars with remaining 1/4 cup blueberries and crumble the remaining crust evenly on top. Return to the oven and bake another 25-30 minutes or until filling is bubbly. Remove from oven and cool completely on a wire rack. Best stored in the refrigerator.