Heat the olive oil in a large skillet over medium heat.
Add the chopped onion and cook for 3-5 minutes, stirring occasionally, until softened.
Stir in the minced garlic and cook for another minute until fragrant.
Add the rinsed black beans, chili powder, and 1 cup (240 ml) of water to the skillet.
Bring to a simmer, then reduce the heat to medium-low.
Cook for about 10 minutes, or until most of the liquid has evaporated.
Remove the skillet from the heat.
Using a potato masher or the back of a fork, mash the beans until the mixture is thick but still has some texture with whole beans remaining.
Stir in 1 cup (240 ml) of the salsa and the corn kernels.
Season with salt and pepper to taste and let the filling cool slightly.
Preheat your oven to 425°F / 220°C. Lightly coat two large baking sheets with cooking spray.
Warm the corn tortillas briefly in the microwave or a dry skillet to make them pliable. Spoon about ¼ cup of the black bean mixture in a line down the center of each tortilla.
Roll it up tightly and place seam-side down on the prepared baking sheets.
Repeat with all tortillas.
Lightly spray the tops of the taquitos with cooking spray.
Bake for 8-12 minutes, or until the tortillas are golden brown and crisp.
While the taquitos are baking, combine the remaining salsa with the chopped cilantro in a small bowl.
Serve the hot taquitos immediately with the cilantro-salsa for dipping.
