Baking Juicy Blueberry Upside Down Cake is straightforward and fun if you follow these steps carefully:

1. Preheat Oven: Begin by preheating your oven to 350°F (175°C). Grease a round cake pan with butter.
2. Prepare Blueberries: In a small saucepan, melt the 1/4 cup of butter over low heat. Once melted, add brown sugar and stir until dissolved, creating a caramel-like mixture.
3. Pour Mixture into Pan: Pour the butter and sugar mixture into the prepared cake pan. Evenly distribute the fresh blueberries on top.
4. Mix Dry Ingredients: In a medium bowl, whisk together flour, baking powder, baking soda, and salt until combined.
5. Combine Wet Ingredients: In another bowl, mix granulated sugar, buttermilk, vegetable oil, egg, and vanilla extract. Whisk until smooth.
6. Combine Mixtures: Gradually add the wet ingredients to the dry ingredients, blending until no lumps remain.
7. Pour Batter: Carefully pour the cake batter over the blueberries in the pan, spreading it evenly to cover them.
8. Bake: Place the pan in the preheated oven and bake for 40-45 minutes or until a toothpick inserted in the center comes out clean.
9. Cool the Cake: Once baked, remove the cake from the oven and allow it to cool in the pan for about 10-15 minutes.
10. Flip the Cake: To serve, use a plate larger than the cake pan. Gently flip the cake out onto the plate so the blueberries are on top. If some blueberries stick to the pan, simply sprinkle them on top of the cake.

These clear and easy steps will have you enjoying a deliciously sweet slice of Juicy Blueberry Upside Down Cake in no time.