Cook rice; set aside. Meanwhile, heat oil in large saucepan over medium heat. Add onion, garlic, jalapeno and cumin; season with salt and pepper. Cook, stirring occasionally, until onions are softened and golden, being careful not to let the garlic burn. Add tomato paste and cook, stirring for 1 minute.
Add one can of beans and mash gently in the pan (a potato masher or fork works great here). Add the second can of beans and the water and stir to combine. Bring to a boil, reduce heat to medium and simmer, stirring occasionally, until thickened, 10-12 minutes, being careful not to let the mixture stick to the bottom of the pot. Add corn; cook to heat through, 2-3 minutes. Stir in onion and garlic powders. Remove from heat; stir in green onions and cooked rice.
Heat tortillas in microwave for about 30-45 seconds or until all are warmed through.
Fill each tortilla with about 2/3 cup bean and rice mixture and 1/4 cup cheese on one side of tortilla. Fold, and hold in sides. Starting from filled end, holding sides in as you work, tightly roll into a bundle. Place on a baking sheet, seam side down, and prepare remaining burritos.
Serve warm immediately, with salsa and sour cream if desired — or, to freeze for later consumption, put the baking sheet of burritos into the freezer for at least 30 minutes, or until very cold so that they don’t come apart in the wrapping process. Remove them from the freezer and wrap each burrito individually in plastic wrap and place all the wrapped burritos in a freezer-safe resealable bag and freeze up to three months.
To reheat from frozen: Remove plastic wrap from the burrito. Poke holes in the top several times with a fork. Microwave on high for two minutes. Gently poke a few more holes in the burrito and microwave for another minute. Be careful as the burrito will be piping hot!