Add the diced strawberries and sugar to a medium pot over medium heat.

Cook for about 45 minutes, smashing half way through with a wooden spoon.

Transfer the jam to a bowl, cover with plastic wrap and pop it in the fridge to chill.

Preheat the oven to 350℉ (175℃). Line a cookie sheet with parchment paper.

Add the flour, sugar and salt to a medium bowl. Whisk together.

Add in the cold, cubed butter. Cut the butter into the flour until the mixture resembles small crumbs.

Sprinkle the crumble mixture evenly onto the middle of the cookie sheet. Bake for 10-12 minutes.

Let it cool, then transfer it to a small bowl and set aside for later use.

Preheat the oven to 350℉ (175℃) if not still preheated. Line an additional cookie sheet with parchment paper.

In a medium bowl, whisk together the flour, baking powder, baking soda and salt.

In a large bowl cream the softened butter and granulated sugar together until fluffy, about 2 minutes.

Add in the egg and vanilla and mix until pale in color and very fluffy.

Add in the white chocolate, and fold it into the cookie dough.

Push ¾ of the dough to the side of the bowl. Flatten ¼ of the dough and spoon ¼ of the jam, then layer again.

Cut the dough in quarters with a rubber spatula and fold each section of dough until the jam is slightly mixed.

Scoop the dough into 22 portions with a 2 tablespoon cookie scoop.

Place the cookie dough scoops at least 2 inches apart and press down lightly.

Bake for 10-11 minutes.

Let the cookies cool on the cookie sheet, then transfer to a cooling rack.

Add the mascarpone and powdered sugar to a medium bowl. Mix together just until combined.

Add in half of the cream and mix just until very soft peaks form.

Add in the rest of the cream and mix until soft peaks form.

Transfer the whipped cream to piping bag fit with a decorative tip.

Pipe whipped cream onto each cookie, sprinkle shortcake crumble on top and add a fresh strawberry slice.