Using a mixer, cream butter, gradually adding sugar and beating well at medium speed. Add egs, one at a time, beating well after each addition.
In a separate bowl, combine flour, baking powder and salt; add to creamed mixture alternating with the sour cream mixture, beginning and ending with flour. Mix after each addition. Stir in vanilla.
Pour into a greased (I use butter covers to grease pie pan) and floured 9x13 cake pan. Bake for 30-35 minutes.
For Icing:
Melt butter; stir in brown sugar. Heat to a boil and lower heat and stir for two minutes. Add milk and stir constantly until boiling again. Cool to lukewarm.
Once cool, gradually add powdered sugar to desired consistency. Add hot water if icing becomes too thick, a tablespoon at a time until it is how you like.
Recipe by Faithful Provisions at https://faithfulprovisions.com/sour-cream-cake-with-caramel-icing/