1. Prepare the Oven and Bundt Pan: Essential First Steps

1. Preheat Oven: Preheat your oven to 350°F (175°C).
2. Grease and Flour Pan: Generously grease a 10-inch Bundt pan with baking spray that contains flour. This will ensure the cake releases cleanly from the intricate details of the Bundt pan.
   • Tip: You can also use shortening or butter to grease the pan, then dust it with flour, tapping out any excess.

2. Prepare the Blueberries: Preventing Sinking

1. Toss with Flour: In a small bowl, gently toss the blueberries (fresh or thawed and drained frozen) with 1 tablespoon of all-purpose flour. This will help prevent them from sinking to the bottom of the cake during baking.

3. Combine Dry Ingredients: Ensuring Even Leavening

1. Whisk Together: In a large mixing bowl, whisk together the remaining 2 ¾ cups of all-purpose flour, baking powder, baking soda, and salt. Set aside.

4. Cream Butter and Sugar: Creating a Light and Fluffy Base

1. Beat Butter and Sugar: In another large mixing bowl, use an electric mixer (handheld or stand mixer) to beat the softened butter and granulated sugar together until the mixture is light and fluffy, about 4-5 minutes. This incorporates air into the batter, resulting in a tender cake.

5. Incorporate Eggs and Vanilla: Adding Richness and Flavor

1. Add Eggs: Add the eggs to the creamed butter and sugar mixture one at a time, beating well after each addition until fully incorporated.
2. Stir in Vanilla: Add the vanilla extract and mix until combined.

6. Add Oil: Ensuring a Moist Crumb

1. Incorporate Oil: With the mixer on low speed, slowly drizzle in the vegetable oil and mix until just combined.

7. Alternate Dry Ingredients and Sour Cream: The Key to a Tender Texture

1. Add in Stages: With the mixer on low speed, alternately add the dry ingredients and the sour cream to the wet ingredients. Begin and end with the dry ingredients.
   • Example: Add about ⅓ of the dry ingredients, mix until just combined, then add about ½ of the sour cream, mix again, and repeat, ending with the remaining dry ingredients.
   • Tip: Don’t overmix the batter. Mix only until the ingredients are just combined and no streaks of flour remain.

8. Fold in Blueberries: Adding Bursts of Juicy Sweetness

1. Gently Fold: Using a rubber spatula, gently fold in the flour-coated blueberries until they are evenly distributed throughout the batter.
   • Tip: Be careful not to overmix, as this can cause the blueberries to burst and make the batter too wet.

9. Bake the Bundt Cake: Achieving Golden-Brown Perfection

1. Pour Batter: Pour the batter into the prepared Bundt pan and spread it evenly using a spatula.
2. Bake: Bake in the preheated oven for 50-65 minutes.
   • Check for Doneness: The cake is done when a wooden toothpick inserted into the center comes out clean. The top should be golden brown and spring back lightly when touched.
   • Note: If the top of the cake starts to brown too quickly, loosely cover it with aluminum foil for the last 5-10 minutes of baking to prevent over-browning.

10. Cool the Cake: Ensuring a Clean Release

1. Cool in Pan: Remove the Bundt pan from the oven and let the cake cool in the pan for about 10-15 minutes. This allows the cake to set and prevents it from breaking when inverted.
2. Invert onto Rack: Carefully invert the Bundt pan onto a wire rack to release the cake.
3. Cool Completely: Let the cake cool completely on the wire rack before adding the glaze.

11. Prepare the Glaze: A Simple Sweet Finish

1. Whisk Together: While the cake is cooling, prepare the glaze. In a small bowl, whisk together the powdered sugar and 3 tablespoons of milk until smooth.
2. Adjust Consistency: Add more milk, 1 teaspoon at a time, until the glaze reaches your desired consistency. It should be thick enough to drizzle but not too runny.

12. Glaze the Cooled Cake: The Final Touch

1. Drizzle: Once the cake is completely cool, drizzle the glaze over the top, allowing it to drip down the sides.
   • Tip: You can use a spoon, a whisk, or a piping bag to drizzle the glaze.