In a large mixing bowl, beat together the butter and Greek yogurt with an electric mixer until smooth, about 2 minutes.
Add the sugar and beat again until light and fluffy, then add in the eggs one at a time. Continue to beat until combined.
Add the lemon juice, lemon zest, and vanilla extract and beat again.
In a medium bowl whisk or sift together the flour, baking powder, and baking soda.
Slowly add the flour mixture to the lemon mixture, alternating with the buttermilk, in increments of 4 each. Beat together just until all of the ingredients are combined and be sure not to overmix.
Generously grease a bundt pan with nonstick cooking spray and spoon 1/3 of the cake batter into the bottom, add 1/2 cup of blueberries to the top of the batter, then add another 1/3 of the cake batter, top with the remaining blueberries and the remaining batter. Smooth out the top of the cake batter with a spatula and bake for 45-50 minutes or until a toothpick comes out clean.
Once the cake has baked, let the cake sit in the bundt pan for 10 minutes on a cooling rack. Run a knife along the edges to loosen the cake and carefully place the cake upside down on a cooling rack. DO NOT remove the bundt pan unless the cake drops. Let the cake sit for 15 minutes, then remove the bundt pan. If the cake doesn't drop, carefully and very gently pat the pan and shake the pan back and forth. Let the cake cool completely.
In the meantime, make the icing. Combine all of the ingredients in a medium mixing bowl and whisk together until smooth. If you want your icing to be thicker, add more powdered sugar.
Spoon the icing all over the cooled cake, top with more blueberries (optional), and enjoy! Alternatively, you can dust powdered sugar on the cake instead of icing.
If you’ve tried this recipe, come back and let us know how it was in the comments or star ratings!