Preheat the oven to 350 degrees and line two cookie sheets with parchment paper.
In a large bowl, mix the egg, brown sugar, granulated sugar, butter, vanilla, and salt together until combined. You can use a mixer or a wooden spoon.
Once everything is mixed, slowly add your flour in batches until a dough forms. Don’t add everything at once -- that will make a mess and make the dough tough to stir.
Using a tablespoon, scoop spoonfuls of dough from the bowl and roll them into balls.
Place the balls on the cookie sheet about 1-2 inches apart.
Press your thumb gently into the middle of each cookie. Fill each indentation with the raspberry jam.
Bake for 10-12 minutes or until the cookies are golden brown.
Let your cookies cool completely before indulging.