In a food processor pulse a few times to mix flour, baking powder, sugar, and salt.
Scatter butter pieces on top and mix until you have butter the size of peas.
Add egg and yolk and process using on/off until it starts to come together. Don’t let it form a ball. It should come together when you pinch it with your fingers.
Turn it onto the counter and press it together to form a flat disk. I put it inside a plastic bag and aid myself with the bag while pressing my knuckles until it comes together. That way I don’t touch the dough unnecessarily.
Refrigerate for 1 hour and up to 2 days.
