In a large mixing bowl, add butter and whip with a hand mixer until creamy.
Continue mixing while adding sugar gradually until fluffy.
Add eggs, one at a time making sure fully incorporated before adding the next egg.
Stir in vanilla
In a separate bowl, combine flour, cream of tartar, salt and baking soda.
Add flour mixture to butter mixture in 1 cup increments, again making sure that it is fully incorporated before adding the next cup.
When it reaches cookie dough consistency, form into a ball and place in the bowl. Cover and chill for a minimum of 4 hours (overnight is best!)
Preheat oven to 375 degrees F
Line a baking sheet with parchment paper.
Roll the dough to approximately 1/8 inch thick.
Cut with cookie cutters. Since making sandwich cookies it's important to cut even numbers of cookies. Half of the cut shapes will have a smaller shape cut from the center (top of cookie sandwich)
Bake all pieces for 6-8 minutes until lightly brown on bottoms. The tops of the cookies will remain light-colored.
Cool completely on a wire cooling rack.
Raspberry Filling
Combine butter, cream cheese, raspberries, and vanilla with 2 cups of the sugar and beat it with a hand mixer until fluffy.
Add additional sugar to the mixture to achieve a spreadable consistency.
chill, covered for 1 hour.
Assembling the Sandwich Cookies
Spread raspberry filling on each of the bottom halves (whole cookies) and top with a cut-out cookie.
You may add sprinkles or other garnish to the centers of the cookies if you wish or leave as is.
Notes
4 inch cookie cutters were used for the cookies and 2 inch cutters for the cutouts. Yeild will fluctuate with the size of the cutter you use.