Matcha Iced Oatmeal Cookies

A classic iced oatmeal cookie gets a yummy makeover with the addition of matcha powder. These thin and chewy matcha iced oatmeal cookies are flavored with warm Vietnamese cinnamon and then coated with a not-too-sweet matcha icing. The best part of these cookies is you only need a whisk and a few mixing bowls to make the cookie dough.

These matcha iced oatmeal cookies have been on my mind all year, and I’m so excited to finally put them on the blog. Iced oatmeal cookies are a classic Christmas dessert, so I thought it would be cool to give them an Asian flair with my favorite ingredient – matcha. These oatmeal cookies are thin, chewy and full of cinnamon flavor, and that flavor unexpectedly pairs really well with the matcha icing. As a bonus, the bitter flavor of the matcha balances out the sweetness from all the sugar really well.

How I developed these matcha iced oatmeal cookies

These cookies are a variation of my oatmeal craisin cookies with a little more brown sugar to make them flatter and chewier. I tested these cookies 5 times, mostly working on the texture of the cookies. If you see some of my test cookies, some were super flat and some were super dry and thick. It was hard trying to get the right consistency and flavor, but I finally nailed it. I found the key was adding more brown sugar than white sugar which yielded a wet dough.

I also tested the matcha icing a few times. I tested 1 tsp, 1/2 tsp, and 1/4 tsp of matcha powder, and found that 1/2 tsp yielded the best flavor and color. 1 tsp of matcha powder made the icing way too bitter and it honestly made the icing look like vomit. Gross 🙁 Feel free to add as much or as little matcha powder as you want.

Ingredients, Substitutions & Adjustments

Oatmeal Cookies

• Unsalted butter – I used browned butter because I wanted that nutty butter flavor in these cookies. No substitutions.
• All purpose flour – Provides structure to the cookies. I tested these cookies with 1-2 tbsp more flour, and found that it led to a thicker cookie whereas these cookies are chewier and thinner. Feel free to use more flour if you want a thicker cookie.
• Baking soda – Makes the cookie airy and tender.
• Salt – Brings out the flavor of all the other ingredients.
• Ground cinnamon – I used Vietnamese cinnamon for these cookies, but feel free to use whichever ground cinnamon is available.
• Light brown sugar – Adds a sweet, molasses-y flavor to the cookies. This can be substituted with dark brown sugar, but note that will make the cookies sweeter, flatter, and chewier.
• Granulated sugar – Adds sweetness to the cookies.
• Egg – Binds the ingredients together and adds richness to the cookies.
• Vanilla extract – Adds flavor to the cookies. Substitute with 1 vanilla bean or an equal amount of vanilla paste. For better flavor, use vanilla paste.
• Rolled oats – I used whole rolled oats for this recipe. You may also use quick oats.

Matcha Icing

• Powdered sugar – This is the main ingredient of all icings. No substitutions.
• Vanilla extract – Adds flavor to the icing. Substitute with 1 vanilla bean or an equal amount of vanilla paste. For better flavor, use vanilla paste.
• Whole milk – Gives the icing its creamy consistency. Use more to make the icing looser or less to make it thicker. Whole milk can be substituted with coconut milk, but some coconut milk has less liquid than whole milk, so you might need to increase the amount you use.
• Matcha powder – Matcha powder provides the matcha flavor and green color to the icing. I love using Aiya culinary grade matcha powder for all my matcha dessert recipes from my matcha cookies to my matcha brownies.

How to make these matcha iced oatmeal cookies

Make the oatmeal cookies

First, brown your butter. Add 3/4 cup of unsalted butter to a sauce pan. Cook over high heat until the butter is melted and lower to medium low. Slowly cook the butter until brown bits start to appear. Pour into a large mixing bowl and set aside to cool.

In a separate bowl, combine 1 cup of all purpose flour, 1/2 tsp of baking soda, 1/2 tsp of salt, and 1/2 tsp of ground cinnamon. Mix and set aside. To the bowl with the browned butter, add 2/3 cup of light brown sugar and 1/4 cup of granulated sugar. Mix until combined. Add the egg and 1/2 tsp of vanilla extract. Mix until combined. Pour the dry ingredients from step 2 into into the wet ingredients. Mix until just combined. Be careful not to over mix. Lastly, add 1 cup of rolled oats to the batter and mix. Cool the dough in the fridge for 30 minutes.

Preheat the oven to 350 degrees F (177 degrees C). Prep 2 baking sheets by covering them with parchment paper. Using a 1.5 ounce cookie scoop (#40 cookie scoop), scoop the batter onto the prepped baking sheets. Make sure the cookies are 2 inches apart. Bake for 10-12 minutes until the edges are slightly brown. Cool for 10 minutes on the baking sheet and then another 10 minutes on a cooling rack.

Prep the glaze and finish the cookies

While the cookies are cooling, combine 1 1/2 cup + 2 tbsp of powdered sugar, 1 tsp of vanilla extract, 8 tsp of whole milk, and 1/2 tsp of matcha powder in a bowl. Mix until a light green glaze forms. Once cool, dip the cookies face down into the glaze and let them dry on the cooling rack. Alternatively, use a pastry brush to brush the glaze on. Personally, I prefer the brushing method.

How do you store these cookies?

These cookies can be stored at room temperature in an airtight container for up to 3 days.

Did you make this dish?

If you made this dish, I would love to see!

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