Preheat oven to 350 degrees.
In a large bowl, sift together flour, powdered sugar, and salt. Set aside
In a stand mixer, beat the butter on low until creamy, stopping to scrape the sides occasionally to incorporate all of the butter for an even creaminess.
Slowly add in the flour mixture and mix until well blended.
Add dough to the cookie press in the shape of your choosing, and press out cookies onto a cold, ungreased baking sheet.
In a small bowl, mix together the meringue powder and warm water.
Brush cookies with the meringue powder + water mixture, then quickly top with sugar sprinkles.
Bake at 350 degrees for 7-9 minutes, until the edges are slightly golden.
Transfer to a rack to cool for 10 minutes.
Spread jam or jelly onto the unsugared sides of cookies and top with another cookie.