Gather all ingredients. Preheat the oven to 325 degrees F (165 degrees C). Line a baking sheet with a silicone mat.
Mix together powdered sugar and butter in a large bowl with a rubber spatula until creamy. Add egg yolk, vanilla, salt, and almond extract; mix well. Blend in flour until just combined.
Use a sorbet scoop to portion dough into 1/2-ounce (about 1 tablespoon) balls. Roll each ball between your palms.
Place several inches apart on the prepared baking sheet.
Use a 1/2 teaspoon measuring spoon to make the 'thumbprint'.
Chill the cookie balls in the freezer for 20 minutes.
Sprinkle granulated sugar over the cookie balls. Fill the cookie thumbprints with lemon curd and fruit jam.
Bake for 13 to 15 minutes depending on your oven.
Let cookies cool on the baking sheet for 5 minutes then move to a wire rack to cool completely.