Heat oven to 350℉/177℃.
Line a sheet pan with parchment paper. Set aside.
With an electric mixer, beat butter and powdered sugar until smooth, about 1-2 minutes.
Add vanilla.
Mix in flour. (You may need to use your hands to bring the dough together.)
Use a 1½ Tablespoon scoop to portion dough onto prepared pan.
Working with one piece of dough at a time, roll into a smooth ball.
Use the back of a rounded measuring spoon, a regular spoon, or your thumb to make an indention in the dough.
Repeat with remaining portions.
Fill indentions with jam. (This will take anywhere from ½-1 teaspoon depending on how deep you made the indentions.)
Bake for 18-20 minutes, or until the cookies are set.