Jam thumbprint cookies are like little bites of happiness! They're soft, buttery, and filled with tangy raspberry jam. They practically melt in your mouth!
Cream together the butter, granulated sugar and confectioners until light and fluffy.
Add the egg yolk, vanilla extract, and salt to the mixture, beating until well combined. Mix in the flour until just combined.
Scoop out portions of dough (about 1 ½ tablespoons each) and roll them into balls. Roll each ball in granulated sugar and place them on the prepared baking sheet, leaving space between each.
Use your thumb or the back of a teaspoon to make a deep well in the center of each ball. Be careful not to make it too wide. Spoon 1 teaspoon of raspberry jam into each well.
Bake for 10-15 minutes, then let the cookies cool on the baking sheet for at least 10 minutes before serving.