• In a large skillet over medium heat, melt the butter.
• Scatter 1 cup butterscotch chips in a single layer over the butter, and remove pan from heat. Do not stir. Set aside.
• Meanwhile, in a large bowl, combine flour, brown sugar, baking powder, and salt.
• Add vanilla, eggs, and butterscotch chip mixture to the dry ingredients, stirring until combined. The butterscotch chips will be quite melted, and will easily incorporate into the batter.
• Fold in remaining butterscotch chips and pecans.
• Line a 13x9-inch pan with foil, allowing it to hang over the edges.
• Spray lightly with non-stick spray.
• Spread batter into prepared pan.
• Bake at 325 degrees for 25-30 minutes, or until edges are golden brown, and a toothpick inserted near the center comes out clean.
• Remove pan to a wire rack to cool completely.
• Lift the blondies by the foil edges to remove from pan.

For brown butter frosting:

• Melt butter in a small saucepan over medium heat, stirring frequently, until golden brown. It will develop brown flecks and a nutty, caramel fragrance, about 10 minutes.
• Remove from heat, and whisk in vanilla.
• Cool for 10 minutes.
• Transfer to a small heatproof bowl or jelly jar, and refrigerate until firm, at least 1 hour.
• In a large mixing bowl, beat the browned butter until creamy.
• Add 4 c. powdered sugar and ¼ c. heavy cream, beating until light and fluffy. You can add a little more heavy cream if needed to achieve desired consistency. It should be thick and fluffy, but spreadable!
• Frost the blondies. Cut into bars.