Cream together butter, mascarpone and sugars for about 5 minutes on medium-high speed with a stand or hand-held mixer. Add your egg and vanilla, and beat together for another minute or so until light and fluffy.
Combine all your dry ingredients in a separate bowl and whisk together. Add dry goods to your butter mixture (in about 2 batches) and beat until just combined, about a minute.
Add your chocolate chips and mix until evenly incorporated.
Roll your dough into two separate logs, cover with plastic wrap and refrigerate at least 2 hours.
You can also scoop dough directly onto your baking sheets lined with parchment or a silpat, cover with plastic and refrigerate at least 2 hours.
When ready to bake, preheat oven to 350 F.
If you rolled your cookie dough into logs, simply remove plastic wrap and slice your dough with a butter knife, making thick half-inch slices. Place dough rounds onto your baking sheet.
Bake for 10 minutes. Let sit and cool completely on baking sheet, because the cookies will be super soft when they first come out.
Enjoy! Cookies last up to a week stored in an air-tight container.