Make the Cake

1. Set your oven to 350°F (175°C) and generously coat a 10-inch bundt pan with cooking spray.
2. Place the blueberries in a small bowl and sprinkle with 1 tablespoon flour. Toss until lightly coated — this keeps them suspended in the batter instead of sinking.
3. In a separate bowl, whisk the flour, baking powder, baking soda, and salt. Set aside.
4. In a large mixing bowl, cream the softened butter and sugar together for about 4–5 minutes until pale and airy.
5. Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.
6. Pour in the vegetable oil and mix until smooth.
7. Add the dry ingredients and sour cream alternately, a little at a time, mixing gently after each addition to maintain a tender texture.
8. Carefully fold the floured blueberries into the batter using a spatula to avoid crushing them.
9. Transfer the batter into the prepared bundt pan and smooth the surface evenly.
10. Bake for 50–65 minutes, checking doneness with a toothpick inserted into the center. If it emerges clean, your cake is ready. If the top darkens too quickly, loosely tent it with foil during the final 10 minutes.
11. Let the cake rest in the pan for 10–15 minutes, then invert onto a wire rack to cool completely.

Prepare the Glaze

1. In a small bowl, whisk powdered sugar with milk, adding a little at a time.
2. Stir until smooth and pourable. Add more milk for a thinner drizzle or less for a thicker finish.
3. Once the cake is fully cooled, spoon or drizzle the glaze over the top.