In a mixing bowl, combine the drained and rinsed black beans, lime juice, minced garlic, cumin, chili powder, salt, and black pepper.
Use a fork or potato masher to mash the black beans to your desired consistency. For a smoother dip, mash more thoroughly; for a chunkier texture, mash less.
Stir in the olive oil to enhance the creaminess of the dip and mix well.
If desired, fold in the chopped cilantro for added freshness.
Transfer the dip to a serving bowl and serve with tortilla chips or vegetable sticks.
For a spicier kick, add a diced jalapeño or a dash of hot sauce to the mixture.
This dip can be refrigerated for up to 3 days; flavors will deepen as it sits.