In a bowl, beat eggs until frothy. Add sugar and beat until thick.
In a Dutch oven, heat half-and-half until almost boiling. Stir 1 cup of the hot half-and-half into eggs; return all to Dutch oven. Cook and stir for 5 minutes or until mixture just comes to a boil (watch carefully because mixture will foam).
Remove from heat and stir in chocolate-flavored syrup, vanilla, cinnamon, and almond extract. Set mixture aside to cool slightly. Cover and chill in the refrigerator at least 6 hours or overnight.
Stir in the whipping cream. Freeze in a 4- or 5-quart ice cream freezer according to manufacturer's directions. Makes about 3-1/2 quarts.