preheat oven to 350°. Line two 15 x 10" baking pans with nonstick foil, leaving 2 inch overhang on each short end.
Prepare each box of brownie mix separately using three eggs, 1/2 cup oil, 1/4 cup water, and 1 teaspoon vanilla.
Spread mixture evenly into prepared pans. Bake 25 minutes or until toothpick inserted in center's comes out clean. Cool completely.
Lifting foil by ends, place brownies on baking sheet. Cover. Brownies can be stacked with foil in between. Refrigerate or store at room temperature until ready to assemble sandwiches.
line 1 baking pan with nonstick foil. Scoop ice cream into pan, spreading evenly. Freeze three hours or overnight, until firm
To assemble, place one sheet brownies on baking sheet. Invert ice cream onto brownies. Remove foil from ice cream. Invert remaining sheet brownies on top. Peel off foil. Cover with plastic wrap. Freeze until serving.
To serve, cut stack in a 10 rows lengthwise and three rose to make 30 sandwiches each 3" x 1.5"
makes 30 sandwiches