1. Preheat oven to 375°.
2. Heat butter in a small saucepan over medium heat; cook 5 minutes or until browned. Remove from heat; add oil. Set aside to cool.
3. Weigh or lightly spoon flours into dry measuring cups; level with a knife. Combine flours, baking powder, and salt, stirring with a whisk. Place butter mixture and sugars in a large bowl; beat with a mixer at medium speed until combined. Add vanilla and eggs; beat until well blended. Add flour mixture, beating at low speed until just combined. Stir in chocolate chips.
4. Drop by level tablespoonfuls 2 inches apart onto baking sheets lined with parchment paper. Bake 12 minutes or until bottoms of cookies just begin to brown. Cool slightly.