Bring whole milk, 1¹⁄₄ cups water, and vanilla bean to a simmer in a 4-quart pot over medium-low heat. Stir in rice and cinnamon sticks and cook, stirring occasionally, until rice is tender, 20-30 minutes. Remove cinnamon sticks and stir in condensed milk mixture, vanilla extract, and salt. Simmer until the rice has absorbed most of the liquid, 10-15 minutes more. Remove pan from heat, stir in ground cinnamon, and let cool slightly. Transfer mixture to twelve 3-ounce ice-pop molds. Transfer molds to the freezer and freeze until slushy, about 1 hour. Insert a popsicle stick into each mold and freeze until pops are solid, about 3 hours more. To release ice-pops from molds, run the bottom of the molds briefly under warm water.