Preheat oven to 350° F. Line an 8” square pan with parchment paper.
In large bowl, whisk eggs; whisk in melted butter and water. Add brownie mix; stir to combine.
Scrape half the batter into prepared pan; bake for 10 min. Scatter caramel pieces over baked brownie; gently press in. Scrape remaining batter overtop and smooth; bake until edges are firm and centre is set, about 30 more min.
Meanwhile, using a hand mixer, beat chilled fudge sauce until light and fluffy.
Refrigerate to cool brownies completely, about 1 hour. Spread fudge icing overtop. Cut into bars or squares.
Tip: To speed up prep time, make the OMG Turtle Caramels and Chocolate Fudge Sauce a day before baking the bars.