1-In a large bowl, cream together butter: In a large bowl, cream together butter and sugar until light and fluffy. Add egg and vanilla extract, beating until well combined. Mix in the strawberry powder to achieve a pink color.
2-Gradually add flour and salt, mixing until: Gradually add flour and salt, mixing until just combined. Form the dough into a ball, wrap in plastic wrap, and refrigerate for 30 minutes.
3-Preheat oven to 350°F (175°C): Preheat oven to 350°F (175°C). Roll out the dough on a floured surface to 1/4 inch thickness. Cut into boat shapes or use an oval cookie cutter. Place on parchment-lined baking sheets.
4-Use your thumb or the back of: Use your thumb or the back of a spoon to create an indentation in the center of each cookie, forming a boat-like shape. Bake for 12-15 minutes until set but not browned. Cool completely.
5-Beat mascarpone cheese, heavy cream, powdered sugar,: Beat mascarpone cheese, heavy cream, powdered sugar, and vanilla extract until smooth and thick. Transfer to a piping bag fitted with a star tip.
6-In a small saucepan, heat strawberry jam: In a small saucepan, heat strawberry jam with water until melted and smooth. Allow to cool slightly.
7-Pipe cream filling into the cookie boats: Pipe cream filling into the cookie boats. Arrange sliced strawberries on top of the cream. Brush strawberries with the jam glaze.
8-Sprinkle shortbread cookie crumbs around the dessert: Sprinkle shortbread cookie crumbs around the dessert for garnish. Refrigerate until ready to serve, but bring to room temperature about 15 minutes before serving for best flavor.