Add in the mashed bananas & blackberries (I combine the two in a Ziploc bag and squeeze until mixed.)
Add in the eggs
Mix all together until combined
In a separate bowl. mix together the flour, baking soda, flaxseed, and salt.
Add the flour mixture and the buttermilk alternately to the creamed mixture, and mix on low or by hand until combined.
If you’re adding chocolate chips/pecans, add to mixture and hand stir to combine
Pour into two greased pans, or mini loaf pans.
If baking in two regular loaf pans, bake at 325 for 40-45 minutes. If baking in mini loaf pans, bake at 325, and begin checking after 20 minutes with a toothpick to see if it comes out clean. (Because each mini loaf size is different, like mentioned above.)