- Preheat oven to 325℉. Line 2 sheet pans with parchment paper.
- In a medium bowl whisk together flour, baking powder, salt, and baking soda.
- In a separate medium bowl whisk together sweetener, oil, egg, and vanilla.
- Stir flour mixture into oil mixture until combined.
- Use a tablespoon to portion dough, then roll into balls.
- Place dough on sheet pans about 2” apart, then flatten slightly with your palm.
- Bake until lightly browned around the edges, 8-10 minutes, rotating pans and switching
racks halfway through baking.
- Let cookies cool on pans for 3 minutes, then transfer to racks to cool completely.
- For the filling, in a large bowl or a stand mixer fitted with the whisk attachment beat together mascarpone, cream, sweetener, and vanilla until light and fluffy.
- Flip half the cookies so the bottom faces up. Transfer filling to a piping bag or a zip-top bag with a bottom corner cut out. Pipe filling onto overturned cookies, then top with remaining cookies, pressing lightly so the filling comes to the edge.
- Serve immediately or keep refrigerated in an airtight container up to 3 days.