1 package (18.3 ounces) brownie mix or your favorite brownie recipe
3 cups DREYER'S or EDY'S GRAND Vanilla Ice Cream, softened
3 cups DREYER'S or EDY'S GRAND Chocolate Ice Cream, softened
Dulce de leche caramel (optional)
LINE 13 x 9-inch baking pan with foil, making sure to leave overhang on sides. Prepare brownie batter according to package directions; pour into prepared pan. Bake according to package directions. Cool completely in pan on wire rack.
LIFT brownie from pan carefully using foil overhang for handles. Cut brownie into 3 rectangles that will fit into 9 x 5-inch loaf pan (use bottom of loaf pan as guide).
LINE 9 x 5-inch loaf pan with parchment paper (simply cut strips to fit in both width and length allowing a little overhang).
PLACE one brownie rectangle into the bottom of the prepared pan. Top with vanilla ice cream, smoothing down top. Top with one more brownie rectangle. Top with chocolate ice cream, smoothing down top. Top with remaining brownie rectangle, pressing down lightly. Fold parchment overhang over top layer; cover tightly with foil. Freeze overnight.
TO SERVE, lift terrine from pan using parchment overhang. Slice into 1-inch pieces. Drizzle with dulce de leche. Store any remaining terrine tightly covered in plastic wrap and foil in freezer for up to 1 month.