To prepare the sopes, place masa harina and salt together in a large bowl and slowly pour in the warm water. Stir the mixture with a fork for several seconds and then switch to clean hands as the dough begins to come together into a ball. Knead the dough several times and cover with a damp cloth. Set aside to rest for 30 minutes.

After the resting period, heat a dry large heavy-bottomed skillet over medium-high heat. Pinch off plum-sized pieces of dough and flatten to a thickness of approximately ½ inch. Have a piece of parchment paper and a glass or other small vessel with a bottom diameter slightly smaller than that of your sopes on hand in order to finish shaping the cakes. Add a sope to the dry skillet and cook for just 1 minute on each side. Remove and immediately press down with your glass with a piece of parchment paper in between; the idea is to form a rim on your sope so that it can better hold your topping. Set aside the warm, formed sope and repeat with the remaining masa.

Once all of your sopes have been formed, add the canola oil to the pan and warm over medium heat.

Working in batches and refreshing your oil as necessary, add the formed sopes and fry until golden, just 2 to 3 minutes on each side. Remove to a paper towel-lined surface to drain and cool.

Meanwhile, to prepare the topping, heat the olive oil in a large heavy-bottomed skillet over medium heat. Add the onion and sauté, stirring frequently, until tender, fragrant, and translucent, approximately 5 minutes. Add the garlic and sauté for just 2 minutes more. Remove and set aside to cool. Place the sweet potato purée in a large bowl and stir in the cumin, ancho, salt, and bacon. Stir in the cooked onion and garlic.

Top each fried sope generously with the sweet potato mixture and serve immediately.