Preheat the oven to 350ºF (177ºC). Grease and flour (or use homemade cake release) two 8" round baking pans. Set aside.

In a medium size bowl, toss together the 3 cups of flour (reserve the remaining Tablespoon for the blueberries in the next step), baking powder, baking soda, and salt. Set aside.

Toss the blueberries in the remaining Tablespoon of flour. Set aside.

In a large bowl with a handheld mixer or the bowl of a stand mixer fitted with the paddle attachment, beat the butter, sugar, and lemon zest on medium-high speed until light and fluffy (about 3 minutes).

Add each egg, one at a time, beating on medium-high speed until fully incorporated, scraping down the sides as necessary. Add the vanilla extract and beat again until combined.

Stir the lemon juice into the milk. Scrape down the sides of the mixer bowl and turn the mixer speed to low. Add the flour in 2 additions, alternating with the milk/lemon juice.

Remove bowl from mixer, add the blueberries (leave behind any flour that did not stick to the blueberries), and stir with a spatula until everything is completely combined and the blueberries are distributed evenly.

Spoon batter evenly into prepared pans and bake 32-34 minutes or until lightly browned on top and a toothpick or cake tester inserted in the center comes out clean. Remove from oven and allow cakes to cool in the pans completely on a wire rack before removing and assembling.

In a medium size bowl with a handheld mixer or in the bowl of stand mixer fitted with the paddle attachment, beat the butter, and cream cheese on medium speed until no lumps remain (about 3 minutes).

Decrease mixer speed to low. Add powdered sugar and vanilla extract. Increase mixer speed to to high and beat until completely combined (approximately 2-3 minutes).

Trim cooled cake layers to create a flat surface (if necessary). You can do this with a large serrated knife or a cake leveler. Place one layer on a plate or cake stand and cover the top with the cream cheese frosting. Spread evenly with an offset spatula.

Place second layer on top, cut surface down. For a sturdier cake, refrigerate at this point for about 10 minutes. When cake is slightly chilled, remove from refrigerator and spread more frosting on the top and around the sides. Serve. Leftovers stay fresh, covered tightly, at room temperature up to 5 days and in the refrigerator up to 1 week.

Make ahead: prepare cakes and frosting up to 1 day in advance. Cover cakes tightly and keep at room temperature or in the refrigerator until ready to assemble. Refrigerate prepared frosting in an airtight container until ready to use. Unfrosted cake layers may be frozen, wrapped tightly, up to 2 months. Thaw overnight in the refrigerator before assembling. Frosted cake can be frozen, wrapped tightly, up to 2 months. Thaw overnight in the refrigerator and bring to room temperature before serving.