Preheat the oven to 350°F (175°C).

In a mixing bowl, cream together the softened butter and granulated sugar until light and fluffy.

Beat in the egg and vanilla extract.

In a separate bowl, whisk together the flour, baking powder, and salt.

Gradually add the dry ingredients to the butter mixture, mixing until combined.

Drop dough by the tablespoon onto a baking sheet.

Bake until cookies are lightly golden, about 10-12 minutes.

Let cookies cool on a wire rack.

In another bowl, whip the chilled heavy cream with powdered sugar until soft peaks form.

Assemble the cookie sandwiches by placing sliced strawberries and whipped cream between two cookies.