Add ingredients to the bowl of a food processor then process until smooth, scraping down the sides of the bowl as needed. Taste then add more salt and pepper if necessary. Scoop the mixture into the bottom of a 9" pie pan then spread into an even layer and refrigerate while making the sweet corn guacamole.
For the Sweet Corn Guacamole:
To a medium mixing bowl add avocados, lime juice, garlic, salt, and pepper then mash with the back of a fork until smooth. Taste then add more salt and pepper if necessary. Add sweet corn and cilantro then stir until combined.
For the Dip:
Spread the Sweet Corn Guacamole on top of the Black Bean Dip then sprinkle on chopped tomatoes and crumbled Cotija cheese. Serve with tortilla chips and crudite.
Notes
I recommend you make then serve this dip this immediately before the guacamole has a chance to brown.