Preheat oven to 375F. Butter a 8x5 loaf pan.
In a large bowl, beat butter and honey well.
Add eggs one at a time and beat well after each egg.
Beat in vanilla until well blended.
Stir in 1 ½ cup flour, baking powder, baking soda and salt.
Mix in yogurt until well combined.
Toss blueberries with 1 tbsp. flour and stir into batter.
Combine oats and brown sugar.
Pour batter into loaf pan and sprinkle with oats and brown sugar mixture.
Bake for 35-45 mins until golden and a toothpick inserted comes out clean.