Preheat your oven to 350°F (175°C) and line a 12-cup muffin tin with cupcake liners. In a medium bowl, whisk together all-purpose flour, baking powder, and salt. In a larger mixing bowl, cream softened unsalted butter and granulated sugar using an electric mixer for about 2-3 minutes, until it's light and fluffy. Beat in the large eggs one at a time, then stir in pure vanilla extract to enhance the cupcake’s flavor.

Gradually add the flour mixture to your wet ingredients in three parts, alternating with whole milk in two additions. Mix until just combined, being careful not to overmix. Next, gently fold in diced fresh strawberries, ensuring they are evenly distributed throughout the batter without mashing them.

Spoon the batter evenly into the prepared muffin liners, filling each about two-thirds full to allow room for rising. Place the muffin tin in the preheated oven and bake for 18-20 minutes. Check doneness by inserting a toothpick into the center of a cupcake; it should come out clean. Once baked, let the cupcakes cool in the pan for 5 minutes before transferring them to a wire rack to cool completely.

While the cupcakes are cooling, prepare the whipped cream frosting. In a chilled bowl, pour in heavy whipping cream, then sift in powdered sugar and a splash of vanilla extract. Using an electric mixer, beat the mixture on medium-high speed until stiff peaks form. This should take about 3-4 minutes.

Once the cupcakes are completely cooled, frost them generously with your fluffy whipped cream. Use a piping bag for a beautiful swirl or simply spread it with a spatula for a more rustic look. Finally, garnish each cupcake with fresh strawberry slices.