Combine cracker crumbs, sugar, and cinnamon in a medium mixing bowl; add 3/4 cup peanut butter and syrup, mixing just until blended. Press mixture evenly into an 8-inch square baking pan; set aside.
Place chocolate morsels in top of a double boiler; place over simmering water, and stir until chocolate melts. Spread chocolate evenly over surface of peanut butter mixture. Swirl remaining peanut butter in warm chocolate; set aside until chocolate cools completely. Cut into 4- x 1-inch bars.