Preheat your oven to 375°F (190°C). Line baking sheets with parchment paper. In a large bowl, cream together the softened butter and granulated sugar until light and fluffy. Beat in the eggs one at a time, then stir in the vanilla extract. In a separate medium bowl, whisk together the flour, baking powder, and salt. Gradually add the dry ingredients to the wet ingredients, alternating with the buttermilk, beginning and ending with the dry ingredients. Mix until just combined. Gently fold in the finely diced fresh strawberries (or crushed freeze-dried strawberries).

Drop rounded tablespoons of dough onto the prepared baking sheets, leaving about 2 inches between each cookie. Bake for 10-12 minutes, or until the edges are lightly golden and the centers are set. Remove from the oven and let cool on the baking sheets for a few minutes before transferring them to a wire rack to cool completely.

While the cookies are cooling, prepare the frosting. In a large bowl, beat together the softened cream cheese and softened butter until smooth and creamy. Gradually add the sifted powdered sugar, beating until well combined. Stir in the vanilla extract and 2-3 tablespoons of milk (or heavy cream) until the frosting reaches a smooth, spreadable consistency. If the frosting is too thick, add more milk a teaspoon at a time. If it's too thin, add more powdered sugar.

Once the cookies are completely cool, spread a generous amount of cream cheese frosting on top of each cookie. For an extra touch of freshness and visual appeal, garnish each cookie with a fresh strawberry slice and a small mint leaf, if desired. Serve immediately or store in an airtight container.