Preheat oven to 350°. Line baking sheets with parchment paper.
For cookies: In a large bowl, beat butter and sugars with a mixer at medium speed, stopping to scrape sides of bowl. Add eggs, one at a time, beating well after each addition. Add vanilla, beating to combine.
In a large bowl, sift together flour, baking soda, salt, cinnamon, and pie spice. Gradually stir into butter mixture. Add oats, almonds, candied cherries, and dried cherries, stirring to combine. Drop by heaping tablespoonfuls onto prepared pans, spacing 1 to 2 inches apart.
Bake until lightly browned, 8 to 10 minutes. Let cool on pans for 5 minutes. Remove from pans and let cool completely on wire racks.
For icing: In the bowl of a stand mixer fitted with the paddle attachment, beat butter, almond extract, and salt at medium speed until creamy, 3 to 5 minutes. Gradually add confectioners’ sugar and cherry concentrate, beating until smooth.
Add a heaping tablespoon of icing to half of cookies. Top with remaining half of cookies and press gently to spread icing.
Recipe by Taste of the South at https://tasteofthesouthmagazine.com/fruitcake-sandwich-cookies/