First make the pastry cream. Cover it with a plastic film to prevent a skin forming on top. When it cools, keep in the fridge.
Preheat the oven to 325°F(165C°). Grease regular size cupcake pan and set aside.
Start making the dough: Combine the flour and baking powder in a bowl and set aside. Place the butter in a mixing bowl and beat on medium speed for 1 to 2 minutes until it is soft with a hand-held mixer or with paddle attachment if using a stand-mixer. Add the sugar and mix until creamy. Add the egg and mix well. Then add the vanilla and mix. When needed, stop the machine and scrape down the sides and bottom of the bowl with a rubber spatula so they are all mixed well. Add the flour mixture and mix until incorporated.
Divide the dough into equally 12 pieces(48grams). Roll them into balls. Press the balls onto bottom and up sides to give a cup shape.
Bake for 8 minutes until the edges are lightly golden brown. The dough will be puffed after 8 minutes. Don't turn off the oven but remove the cupcake pan from the oven. Using the back of a measuring spoon, gently press the center of the cookie cups to give their cup shape again. Bake for additional 6 minutes until the edges become golden brown. Remove the pan from the oven and let the cookie dough cool in the pan for 10-15 minutes. If needed, gently press the center again as soon as you remove the pan from the oven. To remove the cookies from the pan, gently place a toothpick into the bottom corner of the cookie cup and gently lift the cookies up and remove them from the pan.
Place the chopped chocolate into an ovenproof dish and melt in the oven at 210°F (100°C). When the chocolate starts melting, stir the chocolate. Continue melting-stirring as needed.
Assemble: Coat inside of the cookie cups with melted chocolate. Keep the cups in the fridge for 5-10 minutes to let the chocolate set. Besides its good taste, melted chocolate will prevent the cookie cups softening after they are filled with the pastry cream. Spoon almost 1 tablespoon of pastry cream over the melted chocolate. Put the fresh mints and strawberries over the pastry cream. Keep in the fridge.