Get Ready: First, grease your 7x11-inch pan and heat your oven to 350 degrees F. Make sure your squash is already cooked and mashed.
Mix the Filling: In a big bowl, mix together your 3 cups of squash, 1/2 cup of brown sugar, 2 large eggs, 1/2 cup of milk, 1/4 cup of melted butter, 1 tablespoon of flour, 1 teaspoon of vanilla, and 1/2 teaspoon of salt.
Make it Smooth: Use a mixer to beat everything until it's nice and smooth. You don’t want any lumps!
Make the Topping: In another bowl, stir together 1/2 a box of crushed vanilla cookies, 1/3 cup of pecans, 1/4 cup of melted butter, 2 tablespoons of brown sugar, and 1/2 teaspoon of cinnamon.
Put it Together: Pour your smooth squash mix into the pan. Then, sprinkle the crumbly topping all over it.
Bake and ENJOY!!!....Bake for 30 minutes. The top should be golden and delicious. Let it cool for a minute before you dig in.