Preheat oven to 350 degrees F and grease a 9×13 baking dish.
In a large microwave safe bowl, heat butter in 15 second increments until fully melted. Add both sugars and vanilla and beat until smooth, then beat in eggs one at a time.
In a small bowl, sift together the flour, baking powder, and salt. Add the dry ingredients to the wet and mix until just combined. Fold in the pecans.
Transfer batter to the prepared baking dish and bake for 30-35 minutes or until cooked through the center.
