Preheat oven to 350F. Line a 8×8” baking pan with two sheet of parchment paper so that you have “sleeves” for easy removal.
In a food processor, combine the gingersnap cookies and melted butter. Pulse 2-3 times to combine.
Press the crumbs into the prepared pan. Bake for 10 minutes.
In a large bowl, whisk the egg yolks and lemon zest together until creamy, about 2-3 minutes. Whisk in the lemon juice until well-combined.
Gradually pour in the sweetened condensed milk as you whisk until fully incorporated.
Pour the lemon mixture over the baked crust. Bake for 12-15 minutes, until the filling center is set.
Let cool at room temperature for 20 minutes, before cooling completely in the fridge.
To make the meringue frosting, combine the egg whites, cream of tartar, and sugar in a large mixing bowl. Place over a small saucepan with simmering water. Whisk for about 3-4minutes, until the sugar has dissolved.
Transfer the mixing bowl to the stand mixer with whisk attachment while still warm. Whisk on high speed for 5-7 minutes, until the meringue is stiff. Stir in the vanilla.
Top the lemon bars with the meringue frosting.
Enjoy with Klarbrunn Lemon Sparkling Water for a complimentary refreshment!