Lemon Squares

Two days ago, with the help of these lemon squares, I tackled an age old cooking question. A question that has plagued me since I baked cupcakes from my William Sonoma for kids cookbook.  If I don't have baking powder/soda can I replace it with baking soda/powder?  And the logical follow up question, why didn't I learn the answer in my 4 years as a chem major?  If I had run out of baking powder or soda at home, I would have just asked a friendly neighbor.  But alas, I found myself friendly-next-door-neighborless in Boston with a recipe calling for baking soda and only baking powder in sight.

I'm getting ahead of myself.  Before I even got to the baking soda, I made a crust.  This is Mark Bittman's recipe from "How to Cook Everything".   The crust is exceedingly simple, as is the entire recipe.  He suggests you make it in a mixer, but I did it by hand.   All you need to do is mix butter and flour with a little sugar, press it into a 8x8 pan, and bake for 15 minutes.

Then came the filling, which called for eggs, lemon juice, lemon zest, sugar, flour and baking soda.  That's when I just decided to wing it and just use baking powder.

I poured the filling into the crust and put it back in the oven for 20 minutes.  Would it explode?  Fall flat?  Turn green? Or worst, taste bad?  Nope.  They was perfectly delicious: tart, sweet and crumbly.  Bittman says they keep for 2 days, but are still delicious 3 days later.

Lemon Squares
From Mark Bittman's How to Cook Everything

For the crust:
1 stick softened butter (Bittman called for unsalted, I used salted because I like salt in my desserts)
1 c. flour
1/4 c. sugar

For the filling:
2 eggs
2 tbs. lemon juice
1/2 tsp baking soda (or powder!)
Zest of one lemon
1 c. sugar
2 tbs. flour

Confectioners' sugar

1. Preheat the oven to 350.  Cream the butter and sugar.  Stir in the flour.  Either use a mixer or your hands to combine until crumbly.  Press into an 8x8 pan and bake for 15 minutes.

2. Whisk together all the ingredients for the filling.  Pour on top of the hot crust and bake for another 20 minutes.  Cool, sprinkle with confectioners' sugar, then cut into 16 squares.

Keep for a few days, covered