Preheat oven to 350°F (175°C). Line two baking sheets with parchment paper.

In a medium bowl, whisk together flour and salt. Set aside.

Cream butter and sugar until light and fluffy, about 3-4 minutes. Add egg yolks, vanilla, and almond extract, mixing well.

Gradually add flour mixture on low speed until dough comes together. Refrigerate 15-20 minutes if too soft.

Place chopped nuts or sugar in a shallow bowl. Roll dough into 1-tablespoon balls, then roll in nuts or sugar.

Place balls 2 inches apart on baking sheets. Press thumb firmly into center of each cookie to create deep indentation.

Fill each indentation with about 1/2 teaspoon jam.

Bake 12-15 minutes until edges are lightly golden. Cool on pan 5 minutes, then transfer to wire rack.

If indentations puff during baking, press down gently while warm and add more jam if needed.