1. Preheat oven to 375 degrees. Spray a baking sheet with nonstick spray.
2. Bring a medium pot of water to a boil. Add cubed potato, and once returned to a boil, reduce heat to medium. Cook until very tender, 10 – 15 minutes.
3. Drain and transfer potato to a large bowl. Add sour cream, butter, cheese wedges, garlic powder, pepper, and 1/4 tsp. salt. Thoroughly mash and mix.
4. Bring a large skillet sprayed with nonstick spray to medium-high heat. Cook and stir onion until softened and lightly browned, 8 – 10 minutes.
5. Stir cooked onion into potato mixture.
6. Place tortillas between 2 damp paper towels. Microwave for 1 minute, or until warm and pliable.
7. One at a time, spread each tortilla with 1/10th of potato mixture, about 2 tablespoons; tightly roll up into a tube, place on the baking sheet, seam side down, and secure with toothpicks if needed.
8. Spray taquitos with nonstick spray, and sprinkle with remaining 1/8 tsp. salt. Bake until crispy, 18 – 20 minutes. (Don’t worry if they crack a little.) Enjoy!