Preheat oven to 350 degrees F (175 degrees C). Lightly grease an 8x4 inch loaf pan. Use an electric coffee grinder or food processor to grind 1/2 cup flax seed; set aside.
In a large mixing bowl, beat together banana, oil, sugar and eggs. In a separate bowl, mix together flour, baking powder, baking soda, salt, ground flax seed and 1/4 cup whole flax seed. Gradually stir flour mixture into banana mixture. Fold in dates. Spoon batter into prepared loaf pan.
Bake in preheated oven for 55 to 60 minutes, or until a toothpick inserted into the loaf comes out clean.