Heat the panini maker according to the manufacturer’s directions. Drizzle olive oil over each slice of bread and grill the bread, two slices at a time, until they’re toasted, about 2 minutes. For each toast: Criss-cross two slices of bacon on a slice of grilled bread. Lay an avocado half on top of the bacon and smash it with the back of a spoon to spread it around the toast. Squeeze lime juice over the top and season the avocado with coarse salt to taste.