Preheat your oven to 350°F (175°C) and prepare a 9x13-inch baking dish by greasing it lightly or lining it with parchment paper.

In a large mixing bowl, whisk together the granulated sugar and brown sugar if using. Add vegetable oil or melted butter and room-temperature eggs, mixing until smooth and creamy for about 2-3 minutes.

In a separate bowl, combine the all-purpose flour, baking powder, and salt. Whisk until evenly distributed.

Gradually add the dry ingredients into the wet ingredients, folding gently until just combined. Stir in vanilla extract.

Fold in the chopped pecans until evenly distributed in the batter.

Transfer the batter into the prepared baking dish and spread evenly. Bake for 30 to 35 minutes, checking for doneness with a toothpick.

Once baked, allow to cool in the baking dish for about 10-15 minutes before cutting into squares and serving warm or at room temperature.