Put the crème fraîche, whipping cream, and 2 tablespoons confectioners’ sugar into a large bowl. Beat lightly until smooth and just thick, taking care not to overwhisk. Taste and add a little more confectioners’ sugar, if you like.
Place a shortbread on each serving plate. Spoon a large dollop of the creamy mixture on top. Scatter the strawberries and mint over the cream.
Dust the other shortbreads with confectioners’ sugar and rest them on top of the strawberries. Add a mint sprig to each dessert and serve.