Step 1

Preheat oven to 350 degrees F (175 degrees C). Cut 2 sheets of parchment paper to fit in a 15x10x1-inch baking sheet.

Step 2

Place potatoes into a large pot and cover with cold water; bring to a boil. Reduce heat to medium-low and simmer until tender, 7 to 10 minutes. Drain.

Step 3

Heat a skillet over medium-high heat; saute spinach in hot skillet until wilted, 1 to 3 minutes. Remove from heat and squeeze as much liquid out of the spinach as possible.

Step 4

Lightly flour one of the prepared sheets of parchment paper. Unroll 1 can of dough out onto paper. Place dough, paper-side down, onto a 15x10x1-inch baking sheet. Spread dough out to fit baking sheet with about 1/2-inch overhang. Spread potatoes, spinach, bacon, Cheddar cheese, and scallions over dough.

Step 5

Beat 11 whole eggs together with 1 egg white in a large bowl. Pour egg mixture over dough. Season with salt and black pepper.

Step 6

Lightly flour the second prepared parchment paper. Unroll dough onto prepared paper to fit the baking sheet. Discard parchment paper and place dough over the egg mixture on top of the baking sheet. Pinch top and bottom dough edges together to seal the crust, trimming an excess.

Step 7

Whisk remaining egg yolk and water together in a bowl. Cut a few small slits in the top crust and brush egg yolk mixture over the top.

Step 8

Bake in the preheated oven until eggs are set and crust is golden brown, 40 to 45 minutes. Cool slightly before cutting into squares.