I like to make sure my pie dough is prepared before I begin making this pie. Make pie dough the night before because it needs to chill in the refrigerator for at least 2 hours before rolling out and blind baking (next step).

If you need a visual for the crust steps, there are helpful step-by-step photos below this recipe. On a floured work surface, roll out one of the disks of chilled dough (use the 2nd pie crust for another recipe). Turn the dough about a quarter turn after every few rolls until you have a circle 12 inches in diameter. Carefully place the dough into a 9-inch pie dish. Tuck it in with your fingers, making sure it is completely smooth. To make a lovely thick edge, I do not trim excess dough around the edges. Instead, fold the excess dough back over the edge and use your hands to mold the edge into a rim around the pie. Crimp the edges with a fork or use your fingers to flute the edges. (In the pictured pie, I fluted the edges and then crimped them with a fork. Review my how to crimp and flute pie crust tutorial if you need extra help with this step.) If dough is too warm, fluting/crimping will be difficult so you can always chill it in the refrigerator for 5-10 minutes first. After fluting/crimping the edges, chill the pie dough in the refrigerator for at least 30 minutes and up to 5 days. Cover the pie crust with plastic wrap if chilling for longer than 30 minutes. Chilling the shaped dough helps prevent the crust from shrinking.

While the crust is chilling, preheat oven to 375°F (190°C).

Line the chilled pie crust with parchment paper. Fill with pie weights or dried beans. Make sure the weights are evenly distributed around the pie dish. Bake until the edges of the crust are starting to brown, about 15-16 minutes. Remove pie from the oven and carefully lift the parchment paper (with the weights) out of the pie. Prick holes all around the bottom crust with a fork. Return pie crust to the oven and bake for 8 minutes to help set the bottom. Remove from the oven. Brush egg wash/egg white all over the bottom and sides of the warm pie crust. Set pie crust aside. (Crust can still be warm when you add the filling. You can pre-bake the crust/add egg wash up to 3 days ahead of time. Cover cooled crust tightly and refrigerate until ready to fill.)

Reduce oven temperature to 350°F (177°C).

Slice the butter into Tablespoon-size pieces and melt in the microwave in a large heat-proof bowl or in a small saucepan on the stove. (Transfer melted butter to a large bowl if using the stove.) Whisk the oil and granulated sugar into the melted butter. Let it sit for 3-5 minutes to slightly cool. Whisk in 2 whole eggs, 1 egg yolk, and vanilla extract until combined. Add the cocoa powder, flour, and salt and whisk until combined. Batter will be thick. Fold in the walnuts and chocolate chips. Batter will continue to thicken the longer it sits, so immediately spoon and spread evenly into crust.

Bake for 40-45 minutes or until a toothpick inserted in the center comes out with just a few moist crumbs. During bake time, if you find the edges of the pie crust are browning too quickly, apply a pie crust shield or a ring of aluminum foil to protect it. **Err on the side of under-baking because the brownie filling will set as it cools.

Remove pie from the oven. Cool for 20 minutes before slicing and serving. Brownie pie will still be warm and that’s ok. Tastes best served warm!

Cover and store leftover pie at room temperature for up to 2 days or in the refrigerator for up to 4-5 days.