Step 1

Preheat oven to 350F. Lightly spray and line a 9x9 baking dish with parchment paper. The paper is optional but helps lift the cake out for easy slicing.

Step 2

Put the sugar and zest in a food processor and process until the zest is completely incorporated, and the sugar is moist and pale yellow. Note: if you don't have a processor then grate the zest of 1 lemon and mix with sugar by hand.

Step 3

Cream the butter and sugar together in a stand mixer, or in a bowl with a hand held mixer.

Step 4

Beat in the eggs, scraping down the sides of the bowl as necessary.

Step 5

Whisk together the flour, baking powder, baking soda, and salt in a separate bowl.

Step 6

Add the lemon juice and extract to the buttermilk.

Step 7

Alternately add the flour and buttermilk to the creamed sugar and eggs. Begin and end with the dry ingredients. Blend until everything is well combined, but don't over mix.

Step 8

Spoon the batter into the prepared pan and smooth out evenly. Sprinkle the sugar evenly over the entire surface. Note: I know, it seems like a lot, but go with it, it makes a nice crust.

Step 9

Bake on the middle rack for about 30 minutes, or until golden.