Defrost the puff pastry.
In the meantime wash the strawberries, pat dry, and hull them.
Cut the strawberries into quarters lengthwise and place them in a bowl. Sprinkle with white granulated sugar, toss, and set aside.
Preheat the oven to 350 degrees F.
Line a baking sheet with parchment paper.
Roll out the puff pastry on a lightly floured surface one sheet at a time. Use large letter cutters to cut out Ms and Os.
Transfer the letters to the baking sheet and poke holes in the dough with a fork.
Brush each with water. On half of them sprinkle the white granulated sugar over the top and then cover the sugared letters with almond leaves.
Place in the oven and bake for 15-20 minutes or until the pastry letters turn a light golden brown.
Remove from the oven and transfer to a wire rack and let cool completely.
Beat the heavy cream, vanilla extract, powdered sugar, and cream of tartar until stiff peaks form.
Load the mixture into a pastry bag fitted with a large star tip.
Place the cooled puff pastry letters without almonds on a serving platter.
Spritz the cream on top in star shapes. Arrange a layer of the reserved cut strawberries on top.
Place the almond-coated puff pastry letters on top of each. Garnish with mint leaves, sprinkle the powdered sugar over the top, and serve.