1. Preheat your oven to 350°F (175°C) and place a rack in the center. Arrange the unbaked 9-inch deep-dish pie crust in a pie dish if it isn’t already in one, crimp the edges, and set aside.

2. In a large mixing bowl, whisk together the melted, slightly cooled unsalted butter, light brown sugar, and granulated sugar until the mixture is smooth and glossy.

3. Add the eggs one at a time, whisking well after each addition, then whisk in the vanilla extract until fully combined.

4. Sprinkle the all-purpose flour, baking powder, and fine sea salt over the wet mixture. Gently fold with a spatula or wooden spoon just until no dry streaks of flour remain, being careful not to overmix.

5. Fold in the semisweet chocolate chips, milk chocolate chips, and chopped nuts (if using) until they are evenly distributed throughout the batter.

6. Pour the cookie batter into the prepared pie crust and spread it into an even layer. Sprinkle the top with mini chocolate chips if you’d like an extra chocolatey finish.

7. Bake for 35–45 minutes, or until the edges are golden brown and set and the center is puffed and just set but still slightly soft. If the crust edges brown too quickly, tent loosely with foil during the last 10–15 minutes.

8. Remove the pie from the oven and let it cool on a wire rack for at least 30–40 minutes so the center can set and the slices hold their shape.

9. Slice into wedges and serve warm or at room temperature, with vanilla ice cream or whipped cream if desired.

10. Store any leftovers covered at room temperature for up to 2 days, or refrigerate for longer storage and gently rewarm before serving.