Pre-heat oven to 350℉
Remove parchment paper from top of dough if used, or center cutting board with crust on it.
Cut edges of dough, so short side measure 8-9 inches, repeat with longer side measuring about 12 inches in length.
Spoon almond frangipane into center and spread out, leaving a 2 inch outer edge on all sides.
Working with one stalk at a time, move sliced rhubarb pieces onto frangipane, re-creating stalks one at a time until all stalks are used.
Using parchment paper, lift the sides is the crust up and over the rhubarb, working slowly to prevent cracking of crust. Repeat on all four sides, creating a seam at corners by overlapping dough.
Slide galette still on parchment paper onto baking sheet.
Sprinkle with sugar and bake for 25 - 30 minutes until rhubarb has softened and crust is flaky and golden.
Serve with whipped cream.