Remove ice cream from freezer to soften while preparing the base.

Combine brown sugar, oatmeal, pecans, flour and margarine, and spread on a cookie sheet. Bake at 400 degrees F for 10 to 15 minutes.

While hot, crumble half of the mixture onto the bottom of a 13 x 9-inch pan. Drizzle the entire jar of caramel topping over the cookie mixture. Spread the ice cream over the caramel. Top with remaining cookie mixture and 1 jar of hot fudge topping. Freeze until serving time.