Preheat the oven to 350°F (175°C). Line a 9x9-inch square pan with parchment paper, leaving an overhang for easy removal.

Melt the 8 tablespoons butter and 1 cup semisweet chocolate together over low heat, stirring until smooth. Remove from heat and stir in 2 tablespoons oil. Let cool slightly.

In a bowl, whisk the 2 large eggs with the 1/3 cup powdered sugar and 3/4 cup + 2 tablespoons granulated sugar for 1-2 minutes until slightly foamy. Stir in 2 teaspoons vanilla.

Pour the melted chocolate mixture into the egg mixture and whisk until smooth and glossy.

Fold in 1/3 cup Dutch-process cocoa, 1/2 cup flour, and 1/2 teaspoon salt until just combined. Do not overmix; stop when streaks disappear.

Pour the batter into the prepared pan and smooth the top. Bake for 20-22 minutes until the top is shiny and the center barely jiggles.

Cool completely at room temperature for 1 hour, then refrigerate the pan for at least 30 minutes.

In a medium pot, melt 1 cup granulated sugar over medium-low heat without stirring too much until it becomes an amber syrup. Watch closely to prevent burning.

Remove from heat and add the 8 tablespoons butter one at a time, stirring constantly.

Slowly pour in the 1/4 cup heavy cream while stirring. Stir in 3/4 to 1 teaspoon salt.

Pour the warm caramel over the chilled brownies and spread evenly. Sprinkle the 1 cup roughly chopped pecans over the caramel.

Melt the 4 oz milk chocolate with 1 1/2 teaspoons oil until glossy.

Drizzle or spread the melted chocolate over the caramel–pecan layer.

Refrigerate the pan for 1-2 hours until the layers are set. Use the parchment overhang to lift from the pan and cut into 16 squares.