Preheat the oven to 400 degrees. Line a 9 inch round )or something close, you really just want the cookies close to each other and in one layer) baking pan with foil. Heat the butter and brown sugar in a small saucepan on the stove over medium heat, stirring until the sugar is dissolved and the mixture begins to boil. Pour the syrup evenly over the cookies and bake for about 10 minutes or until the sugar smells caramelized. Don't worry if the cookies are not soaked in the syrup, it'll boil and expand while it's in the oven. Remove from the oven, sprinkle with flaked salt, and allow to cool to room temperature. Chop roughly and store in an airtight container at room temperature until ready for use or up to 3 days.
Recipe by oh honey bakes at https://ohhoneybakes.com/pumpkin-cake-with-gingersnap-toffee/