Preparation Set aside 1 cup corn kernels for the syrup. Transfer remaining kernels to a large bowl. Using the handle of a spoon or a butter knife, vigorously scape cobs over bowl to release any remaining bits of kernels and as much corn liquid as possible. Transfer kernels and liquid to a blender. Blend on high speed until liquefied as much as possible (there will still be some small chunks—that’s okay), about 1 minute. Transfer to a sheet of cheesecloth, then wring and twist bundle to release corn liquid into a medium bowl (you should have ¾–1 cup). Discard solids. Add cream, condensed milk, evaporated milk, 2 Tbsp. granulated sugar, 3/4 tsp. salt, and 2 cups water to bowl with corn liquid and whisk to combine. Pour mixture into a 13x9" baking dish. Freeze until icy around the edges, about 30 minutes. Using a fork, scrape granita every 30 minutes until ice crystals are thick, icy, and flaky, about 2 hours. Cover tightly and freeze until ready to use. Meanwhile, bring brown sugar, remaining 6 Tbsp. granulated sugar, remaining 1 tsp. salt, and 1 cup water to a boil in a medium saucepan over medium-high heat. Cook, stirring occasionally, until syrup is glossy and slightly thickened but still runny, 10–15 minutes. Add reserved 1 cup corn, reduce heat to medium-low, and cook, stirring occasionally, until sauce is thickened to the consistency of maple syrup and corn is cooked through, about 3 minutes. Let cool, then chill in an airtight container until ready to serve. Divide syrup and corn among sundae glasses. Top with granita. Sprinkle with cornflakes. Do Ahead: Granita and syrup can be made 5 days ahead. Keep granita tightly wrapped in freezer. Transfer syrup to an airtight container and chill.
Preparation Set aside 1 cup corn kernels for the syrup. Transfer remaining kernels to a large bowl. Using the handle of a spoon or a butter knife, vigorously scape cobs over bowl to release any remaining bits of kernels and as much corn liquid as possible. Transfer kernels and liquid to a blender. Blend on high speed until liquefied as much as possible (there will still be some small chunks—that’s okay), about 1 minute. Transfer to a sheet of cheesecloth, then wring and twist bundle to release corn liquid into a medium bowl (you should have ¾–1 cup). Discard solids. Add cream, condensed milk, evaporated milk, 2 Tbsp. granulated sugar, 3/4 tsp. salt, and 2 cups water to bowl with corn liquid and whisk to combine. Pour mixture into a 13x9" baking dish. Freeze until icy around the edges, about 30 minutes. Using a fork, scrape granita every 30 minutes until ice crystals are thick, icy, and flaky, about 2 hours. Cover tightly and freeze until ready to use. Meanwhile, bring brown sugar, remaining 6 Tbsp. granulated sugar, remaining 1 tsp. salt, and 1 cup water to a boil in a medium saucepan over medium-high heat. Cook, stirring occasionally, until syrup is glossy and slightly thickened but still runny, 10–15 minutes. Add reserved 1 cup corn, reduce heat to medium-low, and cook, stirring occasionally, until sauce is thickened to the consistency of maple syrup and corn is cooked through, about 3 minutes. Let cool, then chill in an airtight container until ready to serve. Divide syrup and corn among sundae glasses. Top with granita. Sprinkle with cornflakes. Do Ahead: Granita and syrup can be made 5 days ahead. Keep granita tightly wrapped in freezer. Transfer syrup to an airtight container and chill.