Preheat oven to 350 degrees. Over-grease and line a 9×13 baking sheet with parchment paper.

|| Vanilla Bean Cookie || Gently melt oil and white chocolate together on the stove or in the microwave. Whisk in the sugar, vanilla bean paste, and the eggs until combined. Add the flour and salt, and mix until smooth. Pour cookie mixture onto the greased baking sheet, spread evenly, and bake in the oven for 10-12 minutes or until set. 

Remove cookie from the oven and let cool for 10 minutes before transferring from the pan. Score and remove the crispy edges. Cut the cookie in half and gently remove from the pan.

|| No Churn Vanilla Ice Cream || Whisk mascarpone and sweetened condensed milk together until light and fluffy. Add the heavy cream, pistachios, and rosewater and continue to whip until soft peeks appear. 

Place one side of the cookie onto a half baking sheet. Smooth the no churn ice cream on top of the cookie from edge to edge and place the other half of the cookie on top. Cover with plastic wrap and freeze for at least 6 hours or overnight.

Remove from the freezer and let sit at room temperature for 5 minutes before cutting and cleaning up the edges. Cut into ten sandwiches and serve or return to freezer wrapped up tightly for up to 2 months.