Step 1Heat a large skillet over medium-low heat. Add the rice and cook, stirring frequently, until fragrant and toasted, about 4 minutes. Transfer the rice to a large bowl, add the canela and 1 cup water, and let stand at room temperature for 2 hours.
Step 2Transfer the rice mixture to a blender and process on high for at least 2 minutes, until consistently smooth.
Step 3Meanwhile, combine the remaining 5 cups water and sugar in a large pitcher and stir until the sugar fully dissolves. Strain the blended rice mixture through a cheesecloth or double-fine-mesh strainer into the pitcher and stir to combine.
Step 4Pour the horchata over ice in cups, then top with some of the chopped cantaloupe and pecans and a drizzle of the prickly pear syrup.