Heat oven to 375°F. Melt butter in small saucepan over medium heat; stir until butter browns lightly, about 2 to 3 minutes; dont let become too dark. Remove saucepan from heat. Immediately stir in brown sugar and flour. Add 1 teaspoon water; mix to make firm, crumbly dough.
Scrape dough into 8-inch-round cake pan; pat dough into a solid even layer over bottom of pan. With a fork, make perforated lines in top of dough, dividing into 12 wedges.
Bake in 375°F oven 20 minutes. Cool in pan on wire rack 15 minutes. Unmold; let cool completely. Cut into wedges along perforated lines.