For the cake: Mix the first 4 ingredients together with electric mixer for 2 minutes. Spray a 9x13 pan with cooking spray. Pour mixture into pan. Bake at 350 for 35 minutes.
Praline topping: In skillet,melt butter and mix in light brown sugar, flour and eggs. Cook for 3 minutes over low heat. Remove from heat and add vanilla extract and pecans. Spread evenly over surface of cooled cake. Bake for 7 minutes at 400 to set the topping.