Preheat the oven to 350 degrees and line a baking sheet with parchment paper or a silicone mat.
Next, slice the strawberries into quarters. (If using blackberries, slice them in half.)
In a medium-size bowl, combine the flour, baking powder, salt, and sugar. Stir with a fork until well blended.
Next, add the butter and cut it into the mixture using two knives or a pastry blender. Work the butter in until it’s evenly dispersed and is smaller than peas.
Add the heavy cream and stir gently until a dough forms.
Sprinkle in the strawberries and fold gently to combine.
Scoop 6 balls of dough onto the baking sheet and top with a sprinkling of coarse sugar (if using). Bake the cookies for 35-38 minutes. (You can also make 12 smaller cookies and bake them for 20-25 minutes.)
Move the cookies to a wire rack to cool completely before serving. The cookies soften as they rest so they’re best when served the same day.