Preheat your oven to 350°F (175°C) and prepare the pan by greasing it with butter or non-stick spray and dusting with flour.

In a large mixing bowl, cream together the softened butter and granulated sugar with an electric mixer until light and fluffy, about 4-5 minutes.

Add the room temperature eggs one at a time, mixing well after each addition until fully incorporated.

Mix in the lemon zest, fresh lemon juice, and whole milk until well blended.

In a separate bowl, whisk together the all-purpose flour, baking powder, and salt until well combined.

Gradually add the dry ingredients to the wet mixture, stirring gently until just combined, being careful not to overmix.

Pour the batter into the prepared mini cake pan, filling each cavity about three-quarters full.

Bake in the preheated oven for 18-22 minutes, until lightly golden and a toothpick inserted comes out clean.

Let the cakes cool in the pan for about 10 minutes before transferring to a wire rack to cool completely.

Whisk together the powdered sugar, lemon juice, lemon zest, and milk until smooth, adjusting the milk for drizzling consistency.

Once cooled, drizzle the icing generously over the cakes and allow it to set for a few minutes.

Garnish each cake with a half slice of lemon and a sprig of fresh thyme before serving.