Mix all ingredients together in a heavy bottom pot. Place over low heat and allow milk to steam but not boil.
In a small bowl whisk 1 cup hot milk into custard powder. Stir mix into milk then continue to cook milk on low for 6-10 minutes or until it has thickened slightly.
Cool completely then strain to remove any lumps and cinnamon stick.
Pour into icicle bags to make custard icicles and knot the open end to secure. Pour into ice molds or 13x9 pan to make ice block.
Place in the freezer and freeze until solid. If making custard blocks, cut into squares for serving.
