1Heat oven to 375°F. In small bowl, mix 1/2 cup Bisquick mix and the brown sugar until well blended. Cut in butter, using fork or pastry blender, until mixture is crumbly; set aside.
2In large bowl, stir 2 cups Bisquick mix, the pumpkin pie spice, walnuts, carrots, raisins and granulated sugar until blended. Stir in milk, oil and egg until blended. Pour into ungreased 8-inch square pan. Sprinkle with streusel.
3Bake 30 to 35 minutes or until toothpick inserted in center comes out clean. Cool 30 minutes before serving. Serve warm.