Tip:I usually make calas when I have leftover rice in the fridge—whether it’s from Monday’s red beans or Chinese takeout. If using leftover rice, add 1-1/2 cups of cooked, cold rice to the batter.
Bring 1 cup of water and a pinch of salt to a boil in a small saucepan. Add the rice, stir once, reduce the heat to low, and cover the pan, cooking 18 to 20 minutes or until the grains of rice are plump and fluff apart with a fork. Turn the rice out onto a parchment paper–lined baking sheet and cool for 15 minutes, then transfer to a plastic container (don’t pack it in). Cover with plastic wrap and poke a few holes in the top. Refrigerate for at least 8 hours or up to 2 days.
Pour enough peanut oil into a large pot to fill it to a 2-1/2- to 3-inch depth and bring to a temperature between 350°F and 360°F over medium heat. Line a plate with paper towels and set aside.
While the oil heats up, place the flour, baking powder, and cinnamon in a medium bowl.
Using a stand mixer or a hand mixer, beat the eggs, sugar, and vanilla on high speed until foamy and tripled in volume, 1-1/2 to 2 minutes. Sift in half of the dry ingredients, add the salt, and mix on low speed until only a few dry streaks remain. Sift in the remaining dry ingredients and mix on low speed for a few turns, then add the rice and mix until the fritter batter just comes together into a loose, roughly textured ball.
Once your oil is hot, dip a teaspoon in the hot oil, then into the batter and scoop out a heaping teaspoonful. Hold the spoon close to the oil and let the batter roll off and into the oil. Repeat with the remaining batter; using a slotted spoon, turn and baste the fritters occasionally, allowing them to become golden brown on all sides. (Fry the fritters in two batches if your pot becomes overcrowded.) If the temperature of the oil dips below 350°F, increase the heat to medium-high. Once the fritters are golden brown, transfer them to the prepared plate to cool slightly. Serve on a small plate drizzled with lots of cane syrup.