Drain the cherries, keeping 2 tablespoons of juice. Halve any large cherries and set aside.
Using an electric mixer, cream together the softened butter, sugar, baking powder, and salt until fluffy. Mix in the egg and almond extract, then gradually add the flour until blended. Roll the dough into 1-inch balls, place on an ungreased baking sheet, and press your thumb in the center of each cookie to make an indentation. Add a cherry or cherry half into each indentation.
Melt chocolate with condensed milk in a small saucepan over low heat until smooth. Stir in 1 to 2 tablespoons of reserved cherry juice as needed to thin the frosting. The frosting should be thick. Spoon about 1/2 teaspoon of frosting over each cherry to cover completely.
Bake the cookies in the preheated oven for about 12 minutes, or until firm and slightly browned. Allow them to cool on the baking sheet for 1 minute before transferring to a wire rack to finish cooling.