Caramel Swirl Cake

My husband declared this "the best cake you have ever made"...need I say more?

Caramel Swirl Cake

For the cake batter:

450g (3 cups) plain (all purpose) flour
4 teaspoons baking powder
½ teaspoon salt
200g (1 cup) sugar
350ml (1½ cups) milk
2 teaspoons vanilla extract
2 eggs
100g (½ cup) butter, melted

Topping mix:

200g (1 cup) brown sugar
2 tablespoons flour
200g (1 cup) butter, very soft (almost to point of melted)

Sweet glaze:

300g (2 cups) icing/powdered sugar
5 tablespoons milk
1 teaspoon vanilla extract

Preheat oven to 350 degrees.
In a large mixing bowl combine together all "batter" ingredients except for butter.
Once mixed, slowly add in the butter and combine.
Pour into a greased 9"x13" baking pan.
Mix together all ingredients for topping mix until well combined.
Pour over cake batter and swirl with a knife.
Bake at 350 for 35-45 until fully baked.
Mix together all the sweet glaze ingredients, set aside until cake is done.
Once cake is done, remove from oven, and while still warm drizzle glaze over cake.