Step 1

Put the squash in a large pot and fill with water. Bring to a boil over medium heat and cook until tender, about 20 minutes. Drain in a fine-mesh sieve and press the squash with the back of a spoon to remove the excess water.

Step 2

Preheat the oven to 350 ̊ F. Transfer the squash to a blender. Add the butter and flour and blend until pureed. Add the sugar, lemon extract and eggs. Blend until smooth. Evenly divide the filling among the pie shells. (If using refrigerated pie dough instead of frozen crusts, ease into three 9-inch pie pans and crimp the edges before filling.)

Step 3

Bake until the filling is set, 45 minutes to 1 hour. Let the pies cool to room temperature before slicing.