Preheat the oven to 375°F.
In a large bowl, whisk together the flour and salt.
Add the vegan butter or vegetable shortening and cut it into the flour mixture until it resembles coarse sand.
Add the cold water and mix until the dough comes together.
Turn the dough out onto a floured surface and knead for 1-2 minutes.
Divide the dough into 8 equal pieces and roll each piece into a ball.
Roll out each ball into a circle, about 6-7 inches in diameter.
In a large skillet, heat the olive oil over medium heat.
Add the onion, red bell pepper, jalapeno pepper, and garlic. Cook for 3-4 minutes, until the vegetables are softened.
Add the cumin, smoked paprika, chili powder, salt, and pepper to the skillet and stir to combine.
Add the black beans and corn to the skillet and cook for an additional 2-3 minutes, until the filling is heated through.
Remove the skillet from heat and stir in the cilantro and lime juice.
Spoon about 1/4 cup of filling onto one half of each dough circle, leaving a small border around the edge.
Fold the other half of the dough circle over the filling and press the edges together with a fork to seal.
Place the empanadas on a baking sheet and bake for 20-25 minutes, until golden brown.
Serve with vegan sour cream or salsa, if desired.