Using a stand mixer or hand mixer and large bowl, cream the butter, shortening, and sugar until light and fluffy.
Beat in eggs, vanilla, and instant pudding mix.
In another bowl, whisk together flour, baking powder, and salt. Gradually add to the butter mixture, a little at a time, mixing between additions.
Scoop out dough with a cookie scoop (or by the tablespoonful) shape it into a ball, and place it on a lined baking sheet. Use your finger or the bottom of a measuring spoon to press into the center to create an indentation. Repeat until all dough is used, placing each cookie about 2 inches apart. Spoon jam into the center of each cookie.
Place the cookies in the refrigerator to chill for at least one hour.
When ready to bake, preheat the oven to 350°F.
Bake for 12-15 minutes or until the edges just begin to turn golden brown. Allow the cookies to cool on the cookie sheet for 5 minutes, then transfer to a cooling rack to cool fully.
Notes
Store cookies in an airtight container at room temperature for up to 3 days, or in the refrigerator for up to one week.For longer storage, fully cooled cookies can be frozen for up to 3 months.