Ingredients

• 2.5 cups fresh blueberries , divided
• 1 teaspoon cinnamon
• 1.5 sticks butter
• 1.75 cups white sugar
• 3 large eggs
• 1 teaspoon vanilla extract
• 1 cup chopped walnuts
• 1 cup all-purpose flour , or more as needed

Instructions

1. 1 Preheat the oven to 350 degrees F (175 degrees C). Grease a 8-inch square baking pan.
2. 2 Cook 2 cups blueberries in a large saucepan over medium heat. Add cinnamon and stir. Smash berries gently using a fork or a potato masher, being careful that hot juices do not splash back. Cook until most of the liquid has evaporated and you have a thick syrup, 8 to 10 minutes.
3. 3 Remove blueberries from heat and stir in butter to melt. Add sugar and stir to combine. Pour in eggs when mixture has slightly cooled, 1 at a time, mixing well after each addition. Pour in vanilla extract and stir to combine. Fold in walnuts. Fold flour gently into mixture. Beat well, 60 to 80 strokes, adding up to 1/4 cup additional flour as needed if batter seems too wet. Add remaining 1/2 cup blueberries and stir to combine.
4. 4 Pour batter into the prepared baking pan.
5. 5 Bake in the preheated oven until a toothpick inserted into the center comes out clean, 35 to 40 minutes. Let cool completely before cutting and serving.

Nutrition per serving