Step 1

In a medium bowl whisk together the flour, baking powder, baking soda, cornstarch and salt. Set aside.

Step 2

In a large mixing bowl combine the sugar, cream cheese and butter. Beat until lightened and creamy. Scrape down the sides and bottom of the bowl and blend again. Add the egg, egg yolk and vanilla. Mix on low until blended, scraping the sides and bottom with a spatula as needed.

Step 3

With the mixer on low, add the flour mixture in three additions blending just until the flour disappears. Scrape down the sides and blend with a spatula. Fold in the strawberries until blended. Cover and refrigerate the dough for 30 minutes to 1 hour.

Step 4

Preheat oven to 350°F. Line a baking sheet with parchment paper and set aside. Place ⅓ cup granulated sugar in a bowl or pie tin.

Step 5

Using a small cookie scoop, portion out scant 1 tablespoon of cookie dough. Roll the dough into a ball, then roll the ball in the granulated sugar. Place 2-inches apart on the prepared baking sheet. Bake for 8 to 10 minutes. The edges should be set and barely beginning to brown. The bottoms should be light brown. Don’t over-bake. Transfer to a wire rack and cool completely before filling.

Step 6

To prevent the cookies from spreading too much, don’t leave the dough balls sitting on a warm pan.

Step 7

Beat the butter, vanilla, salt and jam together in a medium bowl until blended. Combine the powdered sugar and strawberry powder together in a medium bowl. Add to the butter and blend on low until incorporated. Beat on medium speed until fluffy adding milk as needed for desired consistency.

Step 8

Match up pairs of similar sized cookies. Pipe or spread buttercream on the bottom of one cookie. Sandwich together and refrigerate until set.

Step 9

Store cookies in the refrigerator for up to 5 days. Allow them to come to room temperature for 30 minutes or longer before serving.