1Preheat oven to 350 F.
2In a large mixing bowl, combine oil, eggs, vanilla and milk. Add sugar, flour, baking powder and salt.
3Pour half of the batter into a 9x13 baking pan.
4In a small bowl, combine brown sugar and cinnamon. Sprinkle half of streusel on top of batter. Top with remaining batter and sprinkle the remaining streusel on top. Drizzle with melted butter.
5Bake, uncovered, for 25-30 minutes.