Coffee Cake with Cinnamon Crumb and Vanilla Icing

1. Preheat the oven to 350°F (177°C) and line an 8-inch square pan with parchment paper or grease. 
2. Next, create the cinnamon crumb mixture by combining brown sugar, flour, and cinnamon, then cutting in chilled butter until crumbly. Refrigerate this mixture. 
3. For the cake, whisk together flour, baking powder, baking soda, and salt. Beat butter and sugar, then add eggs, vanilla, and sour cream. Mix in the dry ingredients and milk. 
4. Spread half of the batter in the pan, sprinkle half of the crumb mixture, then layer the remaining batter and crumbs. 
5. Bake for 32-38 minutes. 
6. For the icing, whisk together the ingredients and drizzle over the warm cake before serving. 
8. Enjoy!!!