Banana Pecan Waffles

Here's the original recipe from The Happy Housewife, though this one isn't from Toni's personal recipes.

3 cups flour
1 tbsp baking powder
1 tsp baking soda
1 tsp salt
¼ cup packed brown sugar
2/3 cup olive oil (I'm thinking coconut oil maybe)
4 large eggs, beaten
2 tsp vanilla extract
2½ cups buttermilk*
½ cup mashed banana
¼ cup chopped pecans (add more to taste)

Combine first five ingredients in a large mixing bowl and mix well.
In a second bowl, whisk together oil, eggs, vanilla, buttermilk and banana.
Add wet ingredients to dry ingredients and stir until ingredients are just mixed (some lumps are okay).
Fold in pecans.
Cook on a waffle iron.
Serve with butter and syrup.
Note: If you do not have buttermilk, you can add 1 tablespoon of white vinegar for each cup of milk and let it sit for for at least one minute before adding it to the wet ingredients. I have also substituted 1 cup of water for one of the cups of milk without noticing any difference.