In a jar, layer dry ingredients evenly as follows; salt, baking powder, ½ cup flour, cocoa powder, 2/3 cup sugar, chocolate morsels, 1 cup flour, 2/3 sugar, white chocolate chips and walnut chips. When giving as a gift, cover container with lid and attach these instructions.
Preheat oven to 350°F. Spray 8 or 9-inch square baking pan with no-stick cooking spray; set aside.
Combine jar contents in mixing bowl with vegetable oil, water, eggs and vanilla extract. Mix until well blended.
Pour brownie mixture evenly into prepared pan. Bake 30 to 32 minutes. Remove to cooling rack; cool completely. Cut into bars to serve.