Butter: Make sure to use unsalted butter. If using salted butter, make sure to omit the salt. If you are lactose-intolerant, go ahead and use unsalted dairy-free butter.

Vegetable Oil: I like using sunflower oil because I always have a bottle of it on hand. However, you can use other types of vegetable oils (such as canola oil, avocado oil, or olive oil) if you prefer.

Gluten-Free Flour: Make sure to use a good-quality gluten-free measure-for-measure flour (a gluten-free 1:1 substitute for regular all-purpose flour) that is made up of lighter flours/starches (such as rice flour, tapioca starch, potato starch or corn starch) to ensure a lighter and fluffier final texture. I do NOT recommend using a gluten-free flour blend that is made up of heavier flours (such as garbanzo bean flour) as that will result in a denser final texture.

Xanthan Gum: Xanthan gum is the replacement for gluten in gluten-free flours and helps to bind the ingredients together. If your gluten-free flour blend does not already include xanthan gum, make sure to add it in.

Baking Powder & Baking Soda: This recipe uses a mix of both baking powder and baking soda to help the batter rise.

White Sugar: I used white sugar, but cane sugar will work just as well. If you are diabetic or insulin resistant, I highly recommend using granulated monkfruit sweetener (a 1:1 sugar substitute that is zero glycemic index and will not raise your blood sugar).

Eggs: Eggs are necessary to bind the ingredients together, so make sure to add them in.

Vanilla Extract: I like adding a bit of vanilla extract for extra flavor.

Sour Cream: I used sour cream, but plain greek yogurt will work as well. If you are lactose-intolerant, go ahead and use dairy-free sour cream instead.

Buttermilk: You can either use store-bought or make your own buttermilk (mix one cup milk with 1 tablespoon lemon juice and let the mixture sit for 5 minutes). If you are lactose-intolerant, go ahead and use dairy-free buttermilk instead.

Brown Sugar: I used brown sugar, but coconut sugar will work too. Alternatively, if you are diabetic or insulin-resistant, I highly recommend using brown granulated monkfruit sweetener (a 1:1 brown sugar substitute that is zero glycemic index and will not raise your blood sugar).

Cinnamon: I love the flavor of ground cinnamon, and it really adds a beautiful flavor to this cinnamon crumb cake.

Powdered Sugar: Powdered sugar (also known as confectioner’s sugar) has a very fine texture that enables to sugar to be dissolved easily to form a smooth glaze. If you are diabetic or insulin resistant, I highly recommend using powdered monkfruit sweetener (a 1:1 powdered sugar substitute that is zero glycemic index and will not raise your blood sugar).

Storing: To store, place in in airtight container or cover with plastic wrap and store in the refrigerator for up to 4 days. Bring to room temperature before serving.