Gather all your ingredients. Preheat your oven to 350°F (175°C).
In a microwave-safe bowl, place the ¼ cup of unsalted butter. Heat the butter in the microwave until fully melted.
Once the butter is melted, add the granulated sugar and all-purpose flour to the bowl. Whisk the mixture together until it becomes a smooth paste.
Next, break two large eggs into the bowl. Add 1 teaspoon of pure vanilla extract. Whisk these ingredients into the mixture until they're fully incorporated and the mixture becomes smooth again.
Pour 1 cup of semisweet chocolate chips into the bowl, followed by 1 cup of chopped walnuts. Stir these in gently with a spatula or spoon until they're evenly distributed throughout the mixture.
Now, take your unbaked 9-inch pie shell and pour the mixture into it. Make sure to spread it evenly in the pie shell.
Place the pie in your preheated oven and bake for approximately 40-45 minutes. Keep an eye on the pie, you'll know it's done when the middle is set and the top has a beautiful golden brown color.
Remove the pie from the oven and let it cool for at least 30 minutes before serving. This will allow the filling to set properly and make it easier to slice.
Notes
While the traditional recipe calls for walnuts, you can substitute them with pecans for a different flavor profile. Pecans provide a slightly sweeter, richer taste that complements the chocolate perfectly.
Allow your pie to cool completely before slicing into it to prevent it from falling apart.
This pie pairs well with a scoop of vanilla ice cream or a dollop of whipped cream. Enjoy!