Preheat oven to 350.

In a large bowl, combine flour, sugar, oats, cinnamon and salt and mix until combined. Melt the 1/2 cup of butter and add it, along with the vanilla, to the oat mixture. Stir until moistened. This may take a minute or two! Fold in the blueberries – it’s okay if they pop a little bit.

Butter and flour an 8×8 baking pan. Press batter into the pan. Melt remaining butter and drizzle it over the bars. Bake for 20 minutes, the let cool completely – this can take up to 45 minutes! Cut and serve. Can be kept in the fridge or at room temperature in a sealed container.