Preheat the Oven: Start by preheating your oven to 350°F (175°C) to ensure it reaches the right temperature for baking.
Prepare the Pie Crust: Place your unbaked pie crust in a 9-inch pie dish, pressing it gently against the bottom and sides. If desired, crimp the edges for a decorative finish.
Beat the Eggs: In a large mixing bowl, crack four large eggs and whisk them together until they are frothy. This will help incorporate air into the filling for a light texture.
Mix Dry Ingredients: In a separate small bowl, combine 1 cup of granulated sugar, 2 tablespoons of all-purpose flour, 1 teaspoon of ground cinnamon, and 1/4 teaspoon of salt. Stir these dry ingredients together until well mixed.
Combine Mixtures: Gradually add the dry mixture to the beaten eggs, stirring continuously until fully combined. This ensures an even distribution of flavors.
Add Wet Ingredients: Pour in 1 cup of light corn syrup, 1/4 cup of melted butter, and 1 teaspoon of vanilla extract. Mix thoroughly until everything is well incorporated and smooth.
Incorporate Oats: Gently fold in 1 cup of quick-cooking oatmeal (uncooked) into the filling mixture, ensuring that the oats are evenly distributed throughout.
Fill the Pie Crust: Carefully pour the oatmeal filling into the prepared pie crust, using a spatula to spread it evenly if necessary.
Bake: Place the pie in the preheated oven and bake for approximately 45 minutes. The filling should be set but still slightly jiggly in the center when done.
Cool Before Serving: Once baked, remove the pie from the oven and allow it to cool on a wire rack for at least 30 minutes before slicing. This cooling time helps the filling firm up for easier serving.