01 -
Set oven to 350°F. Line an 8x8 inch pan with parchment using two crisscross sheets for easy lifting.
02 -
Mix the softened butter and sugar on high until airy, about 3 minutes. Stir in the salt and flour. Spread it out evenly in the pan.
03 -
Pop it in the oven until the edges just start to brown, about 15-18 minutes. Take it out to cool down.
04 -
Beat together the eggs and sugar for a minute until they look fluffy. Add in the zest, juice, and flour. Pour this mix right over the crust while it's warm.
05 -
Bake until the top looks golden and the mixture is set, roughly 18-20 minutes. Cool fully, then slice into 16 bite-sized squares.