Preheat oven to 350°F / 180°C. Grease your bundt pans and take frozen blueberries out of the freezer
Cream the butter and sugar together until light and fluffy
Add eggs and beat until combined
Add the yoghurt, milk, and, vanilla - mix until combined
In a separate bowl, sift together the flour, baking powder, and salt and then fold into the batter.
Mix in the blueberries by hand. If you want the purple flavour to bleed into the batter a little, let the blueberries defrost slightly before mixing in. If you want a clean batter, add them straight from the freezer
Scoop batter into mini bundt pans. The bundt cavities should be nearly full
Bake for 25-30 mins or until a skewer comes out clean
Once out of the oven, leave in the bundt pan for exactly 10 minutes, then flip them out onto a cooling rack
Make the Blueberry Glaze
Heat blueberries, lemon juice and water in a saucepan over a medium-low heat, just until they begin to bubble gently
Pour into a blender and blitz to make a puree
If you want a super smooth glaze, pass through a sieve to remove any pieces, it's totally fine to skip this step though!
Add powdered sugar and blend or whisk until totally combined
Optional: If you want to lighten the colour slightly, add ½ cup milk or yoghurt to the glaze