In the bowl of a food processor, combine flour, salt, baking powder, and sugar.
Pulse a few times to combine.
Add butter, a few pieces at a time, pulsing after each addition.
Add egg and pulse a few times to combine.
Add cream and pulse until mixture comes together.
Turn out onto a piece of plastic wrap.
Lightly form into a ball and press out into a disc.
Place in refrigerator for 30 minutes.
Turn out dough onto lightly floured parchment paper.
Roll out into a rectangle, 1/4" thick.
Trim edges of pastry.
Using a rectangular cutter, cut out as many rectangles as possible.
Remove dough rectangles to a cookie sheet lined with parchment.
Gather scraps and re-roll.
Cut out rectangles. You should have 18 total between the 2 rolls.