Step 1: Preheat your oven to 350°F (175°C). Generously grease and flour a mini bundt pan or a 12-cup standard muffin tin.
Step 2: In a medium bowl, whisk together the 1 1/3 cups flour, 1/2 tsp salt, and 1/8 tsp baking soda until well combined.
Step 3: In a large bowl or stand mixer, cream together the 1/2 cup softened butter, 2/3 cup granulated sugar, 1/3 cup brown sugar, and lemon zest for 3-5 minutes until light and airy.
Step 4: Beat in the eggs one at a time, then stir in the 1/4 cup sour cream and 1 tsp vanilla extract.
Step 5: Alternately add the dry ingredients and the 1/4 cup milk to the butter mixture, beginning and ending with the dry ingredients. Do not overmix.
Step 6: Divide the batter evenly among the prepared cups. Bake for 18-22 minutes until a tester comes out clean. Allow to cool in the pan for 10 minutes before transferring to a wire rack.
Step 7: To make the glaze, heat 1/4 cup milk and 1/2 tsp lavender in a small saucepan over low heat until simmering. Remove from heat and let steep for 10 minutes. Strain out the lavender.
Step 8: Whisk the lavender milk with 1 1/2 cups powdered sugar, 1/4 tsp salt, and 1/8 tsp vanilla until smooth. Drizzle or dip the cooled cakes into the glaze. Garnish with lemon zest or edible flowers.