Preheat an oven to 325 degrees F (165 degrees C). Grease a 9x5-inch loaf pan.
In a mixing bowl, beat the butter and sugar with an electric mixer until light and fluffy.
Beat in the eggs one at a time, followed by the bananas.
Mix in the self-rising flour and flax seed meal until just incorporated.
Fold in the walnuts.
Pour batter into the prepared pan.
Bake in the preheated oven until a toothpick inserted into the center comes out clean, 20 to 25 minutes. Cool in the pans for 10 minutes before removing to cool completely on a wire rack.
