A chewy and soft Biscoff flavored smash cookie inside and crispy outside, topped with a thin layer of Biscoff frosting and a generous layer of strawberry frosting.
Preheat oven to 350° F (177° C) and lightly grease baking sheets.
In food processor, crush Biscoff cookies into fine crumbs. Alternatively, place Biscoff cookies in Ziploc bag and use rolling pins to create fine crumbs.
Measure flour, baking powder, and salt. Whisk together and set aside.
In mixer, cream butter, shortening, and Biscoff spread on medium-high speed, about 3 minutes or until fluffed together. Scrape sides and bottom of bowl.
Add granulated and brown sugars. Mix on medium-high speed for about 3-5 minutes or until creamed well. Scrape sides and bottom of the bowl.
Add sour cream and mix for 1 minute on medium speed. Scrape sides and bottom of bowl.
Add Biscoff cookie crumbs all at once. Mix on medium speed until incorporated, about 2 minutes. Scrape sides and bottom of bowl.
Add flour mixture all at once. On low speed, mix just until all the flour disappears.
Using a 2” cookie scoop, place dough on lightly greased baking sheets (8 cookies per pan).
Lightly spray bottom of flat-bottomed glass with cooking spray. Dip in sugar and slightly press cookie flat (to about ½” tall). Leave a rough edge around the cookie.
Dip in sugar again before pressing each cookie.
Bake at 350° F (177° C) for 10 minutes. The cookie tops are barely firm. DO NOT overcook!
Allow the cookies to cool in the pan. The cookies will continue to cook slightly.
Biscoff Frosting:
Add all ingredients into a small-medium bowl. With hand mixer, mix until fluffy and smooth. Set aside.
Strawberry Frosting:
In bowl of stand mixer, cream butter and shortening until light and fluffy, about 3-5 minutes. Scrape down sides and bottom of bowl.
Add freeze-dried strawberries all at once and mix medium-low speed until completely incorporated. Scrape down sides and bottom of bowl.
Add dash of salt and then powdered sugar all at once. Mix on low speed until clumps form. Scrape down sides and bottom of bowl.
Add milk. Mix on low speed until milk is not splashing. Scrape down sides and bottom of bowl. Then, mix on medium-high speed until fluffy and light.
Assemble Cookie:
When cookies are completely cool, spread 2 teaspoons of Biscoff frosting on top of cookie (leaving the thin, rough edge around cookie without frosting).
Spread 3 teaspoons of strawberry frosting on top of the Biscoff frosting (leaving a slight edge of Biscoff frosting showing).