20 frozen pancakes, thawed and cut in half
4 eggs, lightly beaten
1 cup milk
1 cup heavy cream
1 teaspoon vanilla extract
2 teaspoons sugar
1 cup flour
1 cup quick-cooking oats
1/2 cup chopped pecans
1 cup brown sugar
1/2 teaspoon salt
1 teaspoon cinnamon
1/2 cup butter, frozen
Grease a 9" x 13" casserole dish and place the pancakes, cut-side down, into the dish so they are standing up.
In a large bowl whisk together the eggs, milk, cream, vanilla, and sugar. Pour this mixture evenly over the pancakes. Then cover the dish with plastic wrap and place in the fridge overnight.
Whisk together the flour, oats, pecans, brown sugar, salt, and cinnamon. Grate the frozen butter into this mixture and using your fingers, work it into the flour and oat mixture, making sure all the butter is coated with flour. The mixture should look like wet sand when finished. Cover this mixture with plastic wrap and also place it in the fridge.
In the morning, preheat the oven to 350 degrees Fahrenheit. Remove plastic wrap from casserole and crumb topping dish. Sprinkle the crumb topping evenly over the pancakes.
Place the casserole into the oven and bake for 45 - 50 minutes, until the center of the casserole is set and the streusel topping is browned and crispy.