Allow the butter and eggs to reach room temperature (the butter should be cool, approximately 65°F, and soft to the touch, but not melted or greasy). Combine the sugar and lemon zest in a single container.
In a separate bowl, mix the flour, baking powder, baking soda, and salt, then set it aside. Prepare an 8x4" loaf pan by greasing it and lining it with a parchment paper sling. Set the pan aside.
Dice the strawberries into ⅛" pieces and toss them with lemon juice. Set them aside.
Preheat oven to 350°F.
Chop the butter into small pieces and place them in a bowl. Beat the butter to soften it. Add the sugar and lemon zest, then mix at medium speed until everything is well blended.
Stop and scrape the sides and bottom of the bowl, as well as the beater, every 90 seconds. Do this at least three times to ensure everything is well mixed.Be patient—achieving the right texture for the butter and sugar mixture can take up to 7 minutes.
As the butter and sugar are creamed together, the sugar granules create small pockets in the butter, incorporating air into the mixture. These pockets trap air, which helps the strawberry pound cake rise during baking.
Next, add the eggs one at a time, allowing the butter to fully incorporate each egg for about 45-60 seconds before adding the next.
Before adding each egg, scrape down the sides of the bowl and the beater. Do this again before you add the dry ingredients.
On the lowest speed, add the dry ingredients in two portions, with the sour cream in between. Let the first portion mix in, then scrape down the sides. Add the sour cream, mixing until it's nearly blended. Finally, add the rest of the flour and mix until only a few streaks of flour remain.
Use a mesh strainer to separate the lemon juice from the minced strawberries. Gently lift and stir the berries to let the juice drain without pressing them through the mesh.Keep the small amount of strawberry lemon juice aside; it will be used in the icing!
Transfer the strawberries onto a paper towel and gently press them with another paper towel to remove any excess moisture.
Drying the strawberry pieces helps to avoid extra moisture in the cake, which can create large air pockets or make the batter gummy around the strawberries.
Gently fold in the strawberries by hand until they are evenly distributed throughout the batter. Stop mixing once everything is well combined.
Use a small offset spatula to spread the batter evenly into the corners and edges of a bundt pan, then smooth the top.
Pressing the batter into the pan helps remove any hidden air bubbles. Smooth the top to ensure even baking.
Bake at 350°F for 60-65 minutes, until a toothpick or small knife inserted into the center comes out with a few crumbs. The internal temperature should reach 209°F.
Let the cake cool in the pan on a cooling rack for 15-20 minutes. Then, run a knife around the edges without parchment and use the parchment to lift the cake onto the cooling rack to cool completely.