1Heat oven to 350°F. Spray bottom only of 8-inch square pan with cooking spray. In medium bowl, beat cake and cookie mix, hot water and 2 tablespoons butter with electric mixer on medium speed until blended. Add gingerroot, sour cream and egg; beat until blended. Pour batter into pan.
2In medium bowl, mix flour, sugar, ginger and cinnamon. Add 1/3 cup softened butter; pinch with fingers until clumps form. Stir in crushed cookies and walnuts. Sprinkle over batter.
3Bake 48 to 50 minutes or until toothpick inserted in center comes out clean. Cool in pan on cooling rack 30 minutes. Serve warm, or cool completely.