Preheat oven to 350 degrees Fahrenheit.

Beat butter and sugar until smooth; mix in yolk and almond extract.

Stir in flour and salt until dough forms.

Roll into 1-inch balls; coat in crushed sliced almonds.

Place on a baking sheet; press a thumbprint into each.

Fill indents with a small scoop of raspberry jam.

Bake 12 to 14 minutes, until almonds are lightly toasted.