Making Lemon Blueberry Donuts is a straightforward process. Follow these steps for delicious results:

1. Preheat the Oven: Preheat your oven to 350°F (175°C). Grease a donut pan or use a non-stick spray.

2. Mix Dry Ingredients: In a large mixing bowl, whisk together the flour, sugar, baking powder, and salt until well combined.

3. Combine Wet Ingredients: In another bowl, beat the egg and then add the milk, vegetable oil, lemon zest, lemon juice, and vanilla extract. Mix until smooth.

4. Combine Mixtures: Gradually add the wet ingredients to the dry ingredients, stirring gently until just combined. Be careful not to overmix; a few lumps are okay.

5. Fold in Blueberries: Gently fold in the blueberries, ensuring they are evenly distributed throughout the batter.

6. Fill the Donut Pan: Spoon the batter into the prepared donut pan, filling each cavity about ¾ full.

7. Bake: Place the pan in the preheated oven and bake for 15-20 minutes, or until the donuts are golden brown and a toothpick inserted into the center comes out clean.

8. Cool: Remove the donuts from the oven and let them cool in the pan for about 10 minutes before transferring them to a wire rack to cool completely.

9. Make the Glaze: In a small bowl, whisk together the powdered sugar and lemon juice until smooth. If the glaze is too thick, add a bit of milk for the desired consistency.

10. Glaze the Donuts: Once the donuts are fully cooled, dip the tops into the glaze, allowing any excess to drip off.