Preheat the oven to 400º.
Liberally spray a 24-cavity mini muffin pan with baking spray.
Reserve 1/4 cup dates for garnish; chop remaining 1/2 cup dates and set aside.
Combine the bananas, softened butter, egg and yogurt in a food processor and pulse until smooth.
Combine the flour, cinnamon, baking powder, baking soda, chopped dates and pecans in a large bowl.
Add to the food processor and pulse until mixed.
Divide the batter among the muffin cavities.
Slice the reserved dates and top each muffin with a date slice.
Bake for 10 minutes or until a tooth pick inserted into the center of a muffin comes out clean.