Remove dough from the refrigerator and roll out on a floured board to a 12" x 16" rectangle.
Cut the sides of the dough to make the edges straight.
Roll the dough over the rolling pin, and then put the rolling pin over a half-sheet pan (18" x 13") that is lined with parchment then unroll the dough on top of the parchment paper. The dough should fit perfectly in the pan.
Mix the almond flour and ¼ cup sugar together then sprinkle onto the tart dough, leaving a 1" border.
Making three rows of peaches, alternate the layers of yellow and white peaches on top of the almond/sugar mixture.
Roll the dough edges over the peaches to create a side crust.
Brush the edges of the dough with beaten egg white and sprinkle with sugar.
Bake in a 350 degree oven for 40 minutes, until the crustis golden brown and the filling bubbly.
Cover any leftover tart with foil or plastic wrap for two days.