Malt Shoppe Memories Ice Cream Cookie Cake

1 pouch (1 lb 1.5 oz) Betty Crocker® double chocolate chunk cookie mix
2/3 cup chocolate-flavor malted milk powder
1/3 cup vegetable oil
2 tablespoons water
1 egg
1/2 cup hot fudge topping
1 cup crushed chocolate-covered malted milk balls
2 cups vanilla ice cream, softened
2 cups chocolate ice cream, softened
1 cup frozen whipped topping, thawed

Heat oven to 350°F. Lightly spray 10-inch spring form pan with cooking spray. Or line 9-inch square baking pan with foil, leaving about 2 inches of the foil overhanging sides of pan; lightly spray with cooking spray.
In large bowl, stir cookie mix, 1/3 cup of the malted milk powder, oil, water and egg until soft dough forms. Press 1/2 of dough into bottom of pan. Bake 12 to 13 minutes or until set. Cool completely, about 30 minutes.
Meanwhile, press remaining 1/2 of the dough into 10-inch circle on large ungreased cookie sheet. After removing cookie crust in spring form or 9-inch pan from oven, bake dough on cookie sheet 12 to 13 minutes or until set. Cool 5 minutes; remove from cookie sheet to wire rack. Cool 15 minutes.
Spread hot fudge topping over crust in springform or 9-inch pan. In medium bowl, break apart large cookie until crumbly. Stir in crushed malted milk balls. Sprinkle 1/2 of the crumbled cookie mixture over hot fudge; press lightly.
In large bowl, combine both softened ice creams and remaining 1/3 cup malted milk powder until well blended. Spread ice cream mixture over crumbs in pan. Gently spread whipped topping over ice cream. Sprinkle with remaining crumb mixture. Cover with foil. Freeze at least 5 hours or until firm. To serve, remove sides of springform pan or lift dessert using foil out of 9-inch pan. Let stand 5 minutes. Use hot wet knife to cut into wedges or squares. Store covered in freezer.