Preheat the oven to 350 degrees F (check your oven racks to make sure they are positioned so that you have enough room for the cake). Set out a 10- to 12-cup nonstick Bundt cake pan but do not grease it (yet!).
In the bowl of a standing mixer fitted with the paddle attachment or a large mixing bowl, cream the butter and Greek yogurt on medium speed until beginning to turn smooth, about 20 seconds. Add the sugar and beat 1 minute. Scrape down the bowl, then add the salt. Beat 1 additional minute until fluffy and lightened in color.
Add the eggs, one at a time, beating well after each addition, stopping to scrape down the bowl once or twice to make sure the ingredients are combining evenly.
In a separate bowl, whisk together the flour, baking powder, and baking soda. Add 1/3 of the flour mixture to the butter mixture, mixing on low speed just until the flour disappears. Add 1/2 of the buttermilk, beating on low to incorporate, then the second 1/3 of the flour mixture, the remaining buttermilk, then the last 1/3 of the flour mixture, beating just until the flour disappears and the ingredients are blended. The batter will look a little shaggy by should not have any large lumps. On low speed or by hand, mix in the lemon zest (I like to zest my lemons right over the mixing bowl to catch every last precious bit of the zest).
Thoroughly grease the bundt pan with nonstick spray (I don’t recommend adding flour as it puts a funny coating on the cake. If you’d like to be extra double sure it doesn’t stick, dust the cake lightly with almond flour or a different nut flour). Spoon 1/4 of batter into the prepared pan, then sprinkle with 1/2 cup of the blueberries. Add the next 1/4 of the batter and sprinkle with the next 1/3 of the blueberries. Continue alternating the cake and berries, ending with the batter. With a spoon or spatula, gently level the cake batter and smooth the top.
Bake the cake for 45 to 55 minutes, or until a toothpick inserted into the center comes out clean. If you are using a dark pan, check at the 40-minute mark as the cake will bake more quickly.
Remove the cake from the oven. Immediately run a thin knife carefully between cake and pan all around the edge to loosen it. Place the pan upside down on a cooling rack. If the cake immediately drops out of the pan onto the rack, remove the pan. If the cake doesn’t drop onto the rack, let it rest for 5 minutes upside down in the pan, then carefully lift the pan off the cake. If the cake STILL feels like it's sticking, give it another 5 minutes upside down, then very gently shake the pan back and forth to loosen and remove it. Let cool completely on the rack.
While the cake cools, prepare the glaze: In a small bowl, whisk together the powdered sugar, lemon juice, and buttermilk until smooth. If you desire a thicker glaze, add a bit more powdered sugar until your desired consistency is reached. Drizzle over the cooled cake. Slice and enjoy!
Notes
TO USE FROZEN BLUEBERRIES: If using frozen blueberries, do not thaw them before adding them to the cake. Be warned that frozen berries tend to “dye” parts of the batter blue. While your cake will look different, it will still taste delicious!
TO USE RASPBERRIES: Blueberries can be swapped for the same amount of raspberries.
TO MAKE GLUTEN FREE: Substitute a GF 1:1 all-purpose flour substitution blend like this one. Baking time may need to be extended by a few minutes.
TO MAKE YOUR OWN BUTTERMILK: If you'd like to make your own buttermilk, mix 1 cup 2% or whole milk with 1 tablespoon lemon juice or white vinegar. Let sit 5 minutes, stir, then use in the recipe as directed.
I do not recommend any substitutions for the sugar or butter or reducing their amounts, as they are key to giving the cake its wonderful texture.
TO MAKE CUPCAKES: This recipe can also be used to make 20 lemon cupcakes! Bake in a lightly greased muffin pan (or line the pan with papers and lightly grease the papers). Use 1/4 cupfuls of batter and bake for 22 to 25 minutes at 350 degrees F. If you’d like to add the blueberries too, toss them with 1 tablespoon of all-purpose flour first, then add them to the batter with the lemon zest, discarding any excess flour that gathers at the bottom of the bowl.
TO STORE: Cover and refrigerate leftover cake for up to 4 days.
TO FREEZE: Wrap cake tightly with plastic wrap and freeze for up to 3 months. Let thaw overnight in the refrigerator before serving.