In small saucepan over medium heat, melt butter and whisk frequently until in becomes a caramel color. This will take 6-8 minutes. Pour the browned butter into a measuring cup, including all the little browned bits at the bottom, to stop the cooking. Set aside to cool off a bit.
Whisk together the flour, baking powder and salt in a small bowl.
Toss the chopped pecans and the butterscotch chips into the flour mixture.
In a medium bowl, blend together the sugars and vanilla.
Add in the cooled, browned butter and mix until well blended.
Add in eggs, one at a time.
Blend in the flour mixture, making sure all is well incorporated and of the same consistency before pouring it into a prepared 13 x 9 x 2 glass pan. Spread evenly as the batter is thick.
Bake at 350°F for about 35 minutes.
Place on a cooling rack to cool completely before cutting.
