One is, that the original recipe included "ammonium bicarbonate" which was cumbersome to pronounce and was therefore changed to "Amerikaner", well, I much prefer the explanation that they were fashioned after the black-and-white cookies, a well known New York favorite.
In any event, these cookies have been sold in German bakeries for quite some time now. The preparation is very similar except for the decorating part. While "Amerikaner" are sold year round with either chocolate or vanilla fondant icing, for the Carnival season they get "dressed up" with colorful faces like the costumes worn by the kids during Carnival season.
To recreate the "Amerikaner" ("Americans") you can easily use the recipe for Mini Black-and-White Cookies from the December 2005 issue of Gourmet magazine.
Recipe for the Cookies
1 1/4 cups AP flour
1/2 tsp baking soda
1/2 tsp salt (I use fine sea salt)
1/3 cup well-shaken buttermilk
1/2 tsp vanilla
7 tbs unsalted butter, room temperature
1/2 cup sugar, superfine
1 large egg, use organic or free range whenever possible
2 3/4 cups confectioner's sugar, sifted
2 tbs light corn syrup
2 tsp freshly squeezed lemon juice
1/2 tsp vanilla
4 to 6 tbs water
1/4 cup cocoa powder
Optional: food coloring, chocolate, licorice, etc.
Preparation of the Cookies
1. Preheat oven to 350 degrees Fahrenheit (160 degrees Celsius)
2. Prepare two baking sheets
3. In a bowl, whisk together flour, baking soda, and salt.
4. In a cup, stir together buttermilk and vanilla.
5. In a large bowl of an electric mixer, beat together butter and sugar until pale and fluffy. Add egg, beating until combined well.
6. Reduce speed to low and add flour mixture and buttermilk mixture alternately in batches, beginning and ending with flour mixture, and mixing just until smooth.
7. Drop rounded teaspoons of batter 1 inch apart onto baking sheets.
8. Bake until tops are puffed, edges are pale golden, and cookies spring back when touched, 6 to 8 minutes total.
9. Transfer to a rack to cool.
Make Icings while Cookies are cooling
1. Stir together confectioner's sugar, corn syrup, lemon juice, vanilla, and 2 tablespoons water in a small bowl until smooth.
2. Transfer half of icing to another bowl and stir in cocoa.
3. With offset spatula spread icing over cookies and decorate as desired.