Cinnabun Cake

I found this recipe recently on the Sisters Cafe blog and have made it a couple of times. It is sooooo delicious. It takes just like a real, frosted, gooey, buttery cinnamon roll. I made it for our family and for a birthday brunch for a friend's birthday. Everyone who has tasted it loves it! It's one of our new favorites!
Cinnabun Cake

Ingredients:
3 cups flour
¼ teaspoon salt
1 cup sugar
4 teaspoons baking powder
1 ½ cups milk
2 eggs
2 teaspoons vanilla
4 T. butter, melted

2 sticks butter, softened
1 cup brown sugar
2 T. flour
1 T. cinnamon
2/3 cups nuts, optional

2 cups powdered sugar
5 T. milk
1 teaspoon vanilla

In an electric or stand mixer mix the flour, salt, sugar, baking powder, milk, eggs and vanilla. Once combined well, slowly stir in melted butter. Pour batter into a greased 9 x 13 inch baking pan.
In a large bowl, mix the 2 sticks of softened butter, brown sugar, flour, cinnamon and nuts until well combined. Drop evenly over cake batter by the tablespoonfuls and use a knife to marble/swirl through the cake.
Bake at 350 for 25-30 minutes or until toothpick comes out nearly clean from center.
Place powdered sugar, milk and vanilla in a large bowl. Whisk until smooth. Drizzle over warm cake. Serve warm or at room temperature.