Preheat your oven to 375 degrees and lightly mist an 8x8 inch pan with cooking spray.

In a medium bowl whisk together 1/2 cup of sugar, baking powder, flour, and salt. Stir in the yolk and lemon zest. Cut in the cold butter until you have pea sized chunks. Spread half of this mixture into your prepared pan. Use the bottom of a glass cup to press firmly down.

Combine the lemon juice, peaches, 1/4 cup sugar, cornstarch and cinnamon in a small bowl. Let the mixture sit for five minutes then use a slotted spoon to transfer your peaches to the crust. Discard any remaining juice.

Crumble the remaining dough mixture over the top and bake for 30 minutes or until golden.