• Preheat oven to 350°. Grease and flour a round or square 9 inch pan. Or alternatively line it with parchment paper and set it aside.

For Streusel Topping:

• Mix butter, granulated sugar, brown sugar, flour and cinnamon together working butter in the mixture till it resembles coarse crumbs. Set aside.

To make Vanilla Cake:

• Sift and mix all dry ingredients, flour, salt, baking powder and baking soda in a mixing bowl.
• Using a handheld or stand mixer fitted with a paddle attachment, beat butter on high speed until creamy, for about a minute. Next add sugar and beat on high speed (for about 2 minutes) until it looks light and creamy. Now add 1 egg at a time, beating well after each addition. Beat in the vanilla extract next. Scrape down the sides and bottom of the bowl with a rubber spatula as needed.
• Add sour cream and flour mix alternating them, in 2-3 additions till all flour and sour cream is used up. Beat well after each addition till flour and cream disappears into the batter.
• Pour batter in the prepared baking pan, top with streusel topping and bake for 25-30 minutes. Check with a toothpick to test for doneness. Allow to cool down completely, before glazing.

Vanilla Glaze:

• Mix confectioners' sugar, heavy cream and vanilla together in a small bowl till well combined and drizzle over the cooled cake.