Combine flour, 1 1/2 tsp. sugar, baking powder and salt in small mixer bowl. Add all remaining crepes ingredients except 1 tsp. butter. Beat at medium speed, scraping bowl often, until smooth (1 to 2 minutes).
Melt 1 tsp. butter in 6 or 8 in. skillet until sizzling. For each crêpe, pour about 1/4 cup batter into skillet; immediately rotate skillet until thin film covers bottom. Cook over medium heat until lightly browned (1 to 2 minutes). Loosen edges of crêpe from pan with wide spatula; turn over. Continue cooking until lightly browned (2 to 3 minutes) and place crêpe on plate. Repeat with remaining batter, placing waxed paper between each. Cover crepes. Set aside.
Melt 1/4-cup butter in 10-in. skillet over medium heat; stir in 1/4-cup sugar, brown sugar and cornstarch. Stir in all remaining sauce ingredients. Continue cooking, stirring occasionally, until sauce begins to thicken (5 to 6 minutes).
Meanwhile, fold each crêpe in half; fold in half again to form triangles. When sauce begins to thicken arrange crepes in skillet. Cook, spooning sauce over crepes occasionally, until crepes are heated through (3 to 4 minutes). Serve warm crepes with sauce.