Start by placing the masa harina into a large mixing bowl. Slowly add the warm water, little by little, stirring with your hands as you go. Once it begins to come together, knead it for 2-3 minutes until the dough is soft and smooth. If it feels too dry, add a bit more water (a teaspoon at a time); if it feels too sticky, continue working it with your hands or let is rest for a few minutes until it's no longer sticks to your hands or the bowl.Shape the masa into a ball, cover the bowl with a towel and let it rest for 10 minutes while you prepare your toppings. Heat up your Frijoles Refritos in a small saucepan on low heat. If they become too dry, add a small amount of warm water. Prepare your salsa if making it fresh.
Now that the masa has rested, knead it for another minute, wetting your hands with warm water if it is slightly dry. The masa should be very soft and moist, but not sticky or difficult to work with. Break the masa into small golf-ball-sized portions and roll into a ball. You can then use a Tortilla Press to make a small, thick disk, or gently shape it with the palms of your hands. Aim for about 3 inches in diameter, and about ¼ inch thick.
Heat a flat griddle or comal over medium heat. Once it’s hot, place the picaditas (or sopecitos) on the griddle and cook for 2-3 minutes on each side. You want them to form a golden crust while remaining soft inside. It's time to flip them when the edges become dry and lift from the pan. They should have a nice, crispy bottom while maintaining that pillowy texture inside. Once done, transfer the picaditas to a plate and cover them with a clean cloth to keep warm.
Once they have cooled slightly, use your fingers and thumb to gently pinch the edges of the masa disc, creating a small "lip" or border around the picadita. This little edge will help hold all your delicious toppings! (If you like your sopes fried, now is the time to fry the masa cakes in a small amount of oil until they are crispy on all sides. I skip this step to keep it simple and light!)
Now it's time to add the toppings! Begin by placing a thin layer of beans on the top of the sope. To that, add a layer of salsa and top with crumbled cheese. Finally, add a drizzle of Mexican crema or sour cream. Serve immediately and enjoy!