Add cubed sweet potato to a medium pot and cover with water. Bring pot to a boil over medium high heat. Cook for 15-20 minutes, until sweet potatoes are soft. Drain pot of water. Let cool for 5-10 minutes..

In a food processor, combine warm sweet potato, 1/2 cup of the black beans, chili powder, cumin, and cinnamon and process until combined. Transfer to a bowl until ready to use.

In a food processor or high powered blender, combine avocado, lime juice and 1/4 cup of the avocado oil. Process until smooth. Add any additional avocado oil until you reach your desired consistency.

Preheat oven to 350F. Brush both sides of the tortillas with the tablespoon of avocado oil. Bake for 10-12 minutes, flipping half way through, until the tortillas are crunchy and slightly golden brown.

Top tortillas with sweet potato mixture. Sprinkle with remaining black beans, onion and bell pepper. Spoon a dollop of avocado cream on top of the tostada.

Serve immediately.