Add all the dry ingredients into a mixing bowl. Beat in the butter one tablespoon at a time until combined and the dough begins to form.
Wrap dough in plastic wrap and flatten into a disc.
Refrigerate for about 30 minutes until the dough is firm.
Lightly flour your work surface with cocoa powder and roll dough to a ¼ inch thickness.
Using a cookie cutter (e.g., 2 inch rough Linzer cookier cutter), cut out cookie shapes and place on baking pan lined with a silicon mat or parchment paper.
Refrigerate cookies for 15 minutes.
Bake at 300F for 10 minutes. Cool.
Filling
Crush the freeze-dried strawberries into a powder and set aside.
Gently melt the white chocolate and water together in a small pot/saucepan. Cool to room temperature.
In a mixing bowl, add the butter and melted white chocolate mixture and beat on medium speed to combine. Then add the powdered sugar, crushed freeze-dried strawberries, and salt. Beat at medium-high for several minutes.
Assembly
Sandwich the filling between two cookies.
Enjoy!
Notes
Crush the freeze-dried strawberries by putting the strawberries in a ziplock bag and use a rolling pin to roll over them. You could also save a step and roll over the original bag that the strawberries came in. Make sure to allow the air in the bag to escape.