• Preheat oven to 350 degrees F
• Line an 8x8 inch baking pan with parchment. Set aside

Crust

• In a large bowl, combine flour, butter and powdered sugar until crumbly. When squeezed in your hands, the dough should hold together. Transfer to the lined baking pan, and press the dough into the pan evenly.
• Bake for 15 minutes. Remove from oven and set aside.

Filling:

• Combine eggs, brown sugar, melted butter, baking powder, salt and vanilla in a large bowl (use the same bowl as the crust - it saves dishes!). Whisk until combined.
• Pour over crust, and sprinkle with pecans or raisins, if using, and bake for another 20-25 minutes, or until the filling has set and the top has browned.
• Allow to cool completely in the pan before removing, and cutting into bars or squares. If you pop them into the fridge, they’re easier to cut.