Jacob Van Patten pours a refreshing summer cocktail into his creative take on lemon bars, which took the overall blue ribbon at the Iowa State Fair.
In a small bowl, combine rum and chopped mint; let stand 20 minutes.
Meanwhile, preheat oven to 350°. Lightly grease a 13×9-inch baking pan.
In a large bowl, beat butter with a mixer on medium 30 seconds. Add 1/2 cup powdered sugar; beat until combined. Stir in 1 3/4 cups flour until just combined. Press into bottom of prepared pan. Bake until set and slightly golden, 20 to 22 minutes.
Meanwhile, in a large bowl, whisk together eggs and granulated sugar. Add the remaining 1/4 cup flour and the salt; whisk until blended. Whisk in lime zest, lime juice and milk. If desired, whisk in food coloring.
Place a strainer over a small bowl; pour rum mixture into strainer. Press with the back of a spoon to squeeze liquid from chopped mint; remove and discard mint. Whisk strained liquid into egg mixture until well combined. Pour over partially baked crust. Bake until center is set, 22 to 25 minutes more. Cool completely on a wire rack, about 1 hour. Just before serving, dust with additional powdered sugar. Cut into bars and garnish with whole mint leaves. Store bars in the refrigerator.