Heat about 1 inch of oil to 350ºF. Fry the tortilla squares in batches, avoiding overcrowding, until golden and crispy. Remove and lightly season with salt.
If using fresh corn, remove the husk and silk, then rinse and cut the kernels from the cob.
In a large pot over medium heat, melt the butter. Add the corn and cook for 2–3 minutes, stirring occasionally.
Pour in the water, add epazote and salt (see notes), and mix well. Cover and cook for 12–15 minutes, or until the corn is fully cooked but still firm, with a lightly seasoned broth. Remove from the heat.
Serve warm in a bowl with some of the broth. Top with mayo, crema, a squeeze of lime juice, Cotija, and ground chile de árbol. Add a drizzle of hot sauce and the crispy tortilla squares (totopos).
Stir gently to combine all the flavors, then enjoy!