Buttery Cinnamon Zucchini Crumb Cake

Ingredients for Buttery Cinnamon Zucchini Crumb Cake
For the Cake:
1½ cups all-purpose flour
1 tsp baking powder
½ tsp baking soda
1½ tsp ground cinnamon
¼ tsp nutmeg (optional)
¼ tsp salt
½ cup unsalted butter, softened
¾ cup granulated sugar
¼ cup brown sugar, packed
2 large eggs
2 tsp vanilla extract
½ cup sour cream (or plain Greek yogurt)
1½ cups finely grated zucchini (squeezed dry)
For the Crumb Topping:
¾ cup all-purpose flour
½ cup brown sugar, packed
1 tsp ground cinnamon
6 tbsp cold unsalted butter, cubed
For the Glaze (optional):
½ cup powdered sugar
1–2 tbsp milk
½ tsp vanilla extract
Tools You’ll Need
8×8-inch baking pan
Parchment paper
Mixing bowls (one large, one medium, one small)
Electric mixer or whisk
Grater for zucchini
Pastry cutter or fork (for the crumb topping