Combine flour, salt, baking powder, and sugar in the bowl of a stand mixer fitted with the pastry beater or the flat beater.
Mix on low to combine.
Add butter.
Mix on low/medium-low speed until butter is broken down.
Add egg and cream.
Mix on low until just incorporated. Do not over mix.
Turn out onto a piece of parchment paper and divide in half.
Wrap each half in plastic wrap.
Place in refrigerator for 30 minutes.
Working with one piece of dough at a time, unwrap and place on lightly floured parchment paper.
Roll out into a rectangle, ¼" thick.
Using a 4½ inch x 2¼ inch rectangular cutter, cut out 9 rectangles.
Transfer dough rectangles to a cookie sheet lined with parchment.
Repeat with 2nd piece of dough.