In a large mixing bowl, combine oil, eggs, vanilla and milk.

In a separate bowl, blend sugar, flour, baking powder and salt.

Add the flour mixture to the egg mixture and stir well to combine. Pour half the batter into a 9×13 pan.

In a third bowl, prepare streusel by mixing brown sugar and cinnamon.

Sprinkle half the streusel over the batter in your baking pan. Top with remaining batter and sprinkle the remaining streusel on top.

Drizzle with melted butter.

Bake uncovered at 350 for 25-30 minutes. Store in airtight container.