Preheat oven to 350˚F.
Lightly spray a mini bundt pan with cooking spray and set aside.
Place flour, baking powder, baking soda, and salt into a mixing bowl and whisk together. Set aside.
In another mixing bowl beat together butter and sugar until light and fluffy.
Add the eggs, one at a time, and continue to beat together. Stir in vanilla.
Add dry mixture to the wet mixture, alternating in thirds with the buttermilk. Stir until completely mixed together.
Fold in the citrus zest until just combined.
Divide batter into the mini bundt molds, filling each about 2/3 full.
Bake the cakes in the oven for 18 to 22 minutes or until a toothpick comes out clean when inserted into the center of each cake.
Allow cakes to cool for 10 minutes, remove them from their molds and continue to cool completely.
Glaze: Whisk powdered sugar and lemon juice together until a smooth glaze forms. Add milk, as needed, to thin glaze.
To assemble: Pour glaze over each cake until well coated. Top with fresh lemon zest and edible flowers, if using. Serve.