Heat oven to 325 and line an 8x8 square baking pan with foil and butter or spray with cooking spray.

Melt butter in a saucepan over medium-high heat. Keep cooking until butter stops foaming and bubbling, you will notice the browned bits forming at bottom of pan, scrape those up with a wodden spoon. Remove from heat; immediately add sugar, cocoa, 2 teaspoons water, vanilla, and salt. Stir to blend. Let cool 5 minutes (mixture will still be hot). Add eggs, beating hard with a wooden spoon to blend after each egg addition. When mixture looks thick and shiny, add flour and continue stirring with a wooden spooning until blended.

Pour batter into prepared baking dish and spread to level out. Drop five tablespoons of tahini over the batter separate from eachother. With a toothpick or a knife, swirl the tahini gently with the batter. You can create any kind of swirled design you like. Bake at 325 for about 35 - 40 minutes, a toothpick in the center should come out mostly clean, and the brownies should be kind of pulled away from the sides of the pan.

Cool completely and then pull from the pan with the foil overhang.