Prep the oven and baking dish. Heat oven to 350°F. Mist a 9 x 13-inch baking dish with cooking spray.

Mix the dry ingredients. In a small mixing bowl, whisk together the flour, baking soda, baking powder and salt until combined. Set aside.

Mix the batter. In the bowl of a stand mixer, cream together butter and granulated white sugar on medium-high speed for 2 minutes until light and fluffy. Add vanilla and eggs to the mixture, one at a time, beating well after each addition. Add half of the flour mixture to the butter mixture and mix on medium-low speed until just combined. Add in half of the sour cream and mix until combined.  Repeat with the remaining half of the dry ingredients mixture, followed by the remaining sour cream, mixing until combined.

Prep the cinnamon-sugar topping. In a separate small bowl, whisk together the granulated white sugar, brown sugar, ground cinnamon and nuts (if using) until combined.

Layer the batter. Pour half of the batter into the prepared baking pan and spread it in an even layer. Sprinkle half of the cinnamon-sugar topping evenly on top of the batter. Add the remaining batter by spoonfuls evenly on top of the cinnamon-sugar topping (this makes it more easy to spread), then gently spread the batter out into an even layer. Sprinkle the remaining cinnamon-sugar topping evenly on top of the batter.

Bake. Bake for 30 minutes, or until a toothpick inserted in the middle of the cake comes out clean. Transfer the baking dish to a wire rack and let it cool for at least 10-15 minutes before serving.

Make the glaze. Meanwhile, if you would like to use a glaze, whisk the powdered sugar and 1 teaspoon milk together until combined. Add an extra teaspoon of milk if needed to thin the glaze to a drizzle-able consistency. Or if it seems too thin, add extra powdered sugar.

Serve. Drizzle the glaze over the top of the warm coffee cake. Slice, serve and enjoy!