Make the dough

• Mix the butter with the powdered sugar
• Add the egg yolk and vanilla extract and mix
• Add the flour and salt and mix to form a dough

Chill the dough

• Wrap the dough and let it rest in the fridge

Shape the cookies

• Divide the dough into equal pieces and roll into balls
• Use your fingers to indent a heart shape in each ball
• Fill the indents with jam

Bake

• Bake at 350F until lightly golden