Brown the butter in a sauce pan. Cool to room temperature before making dough.
Preheat oven to 350*F.
Once the butter is cooled, add the sugars and salt and mix until combined.
Add the egg and mix for a minute or two until all of the egg is incorporated and the mixture is smooth and glossy.
Add the vanilla extract and stir to combine.
Sift the flour and baking soda over the wet ingredients and mix until a soft dough forms.
Smooth the dough out into an even layer on the bottom of the bowl.
Add the three tablespoons of strawberry jam and swirl into the dough using the spatula. Do not mix into the dough, you want pockets of jam in the cookie dough.
Using a tablespoon or a 1 ounce cookie scoop, scoop 6-8 cookies per parchment lined baking tray.
Bake one tray at a time in a 350*F oven for 8-10 minutes. The cookies should be slightly golden brown when done.
Allow to cool on wire rack and sprinkle liberally with flaked sea salt.
Enjoy!