First Step: Prep oven and ingredients Preheat your oven to 400°F (204°C). Gather all ingredients, beat the eggs in a large bowl until smooth, and have your unbaked 9-inch pie crust ready in your pie dish.

Second Step: Combine filling components In the bowl with beaten eggs, add granulated sugar, all-purpose flour, buttermilk, salt, melted butter, and vanilla extract. Whisk vigorously until the mixture is well combined and smooth, with no lumps remaining.

Third Step: Pour filling and prepare topping Pour the filling mixture slowly into the unbaked pie crust, spreading evenly. Lightly sprinkle cinnamon powder over the top surface in an even layer to create the signature crunchy topping.

Fourth Step: Initial baking Bake the pie at 400°F for 10 minutes to set the edges of the crust firmly. This helps keep the shape and prevents overbrowning during the longer bake.

Final Step: Continue baking and cooling Lower the oven temperature to 350°F (175°C) and bake the pie for another 50 minutes. Test doneness by inserting a thin knife into the center; it should come out clean. If the crust edges brown too quickly, cover them with foil or pie shield to protect during baking. Remove from oven and allow pie to cool completely before slicing and serving. The pie can be enjoyed warm, at room temperature, or chilled. Any leftover filling can be baked separately as a crustless pie for additional servings.