Preheat oven to 350°F (175°C).

Cream together oleo and sugar until light and fluffy.

Beat in eggs one at a time, mixing well after each addition.

In a separate bowl, sift together flour, baking powder, salt, and baking soda.

Gradually add the dry ingredients to the wet ingredients, alternating with buttermilk, beginning and ending with the dry ingredients.

Mix in vanilla, mashed bananas, and chopped pecans until just combined.

Pour batter into greased loaf pans.

Bake for 50-60 minutes, or until a wooden skewer inserted into the center comes out clean and cake begins to pull away from sides of the pan.

Let cool in pans for 10 minutes before transferring to a wire rack to cool completely.