Make the Cookie Bases:

1. In a large bowl, whisk together flour, baking soda, and salt. Set aside.
2. In another bowl, use an electric hand mixer to cream together butter, oil, and sugar until smooth.
3. Beat in the egg and vanilla until everything is well combined.
4. Slowly incorporate the dry ingredients into the wet mixture, mixing only until the dough comes together.
5. Roll dough into 24 balls (27 grams each) and press into greased muffin pan cavities to form shallow crusts.
6. Chill for 30 minutes (or freeze for 15 minutes). Meanwhile, preheat oven to 375°F (190°C).
7. Place muffin pans on a preheated baking sheet and bake for 12 minutes until lightly golden.
8. Remove from oven and press centers down to create wells. Cool for at least 15 minutes.

Make the Filling:

1. Mix all filling ingredients in a medium bowl until smooth.
2. Spoon about 1 tablespoon of filling into each cooled crust.
3. Lower oven temperature to 350°F (175°C) and bake for 12 more minutes.
4. Cool completely in pans before removing gently with a knife.

Decorate:

1. Whip the heavy cream to stiff peaks.
2. Pipe onto each cookie using a star tip for a festive finish.