Giant Gluten Free Costco Copycat Apple Streusel Muffins

For those of you who’ve remained invested in this epic saga of the gluten free Costco copycat muffins, this is your post! The fifth installment in our adventure, heaped with apples and buttery crumb topping and vanilla glaze: these GIANT gluten free apple streusel muffins, à la our favorite bulk grocery store chain. I remember that, as a kid facing the trays of massive muffins in the Costco bakery section, these apple streusel creations seemed very “adult.” Something about the elegance of the crumb topping and the criss-crosses of white glaze just had the air of “posh adult breakfast.” Now, as an adult, I’m not sure where I got that idea because my breakfasts are generally not at all posh and not at all giant muffins (though very much considering changing that because all of these giant muffins are way too easy not to make), but hey. I can confirm that if I wanted a posh breakfast, a pastry and tea for instance, these would be the way to go. They’re incredibly moist, packed with grated tart apples (not chunks, the grated lends a bit more softness to the crumb), cinnamon, and topped with my new favorite thing to make: streusel! (fancy German word for “crumbs” (sort of, not really) – one of the many things that’s much more fun-sounding not in English).

For those of you new to the GIANT MUFFIN SAGA, do yourself a favor and check out, and then make, all of the other ones we’ve made thus far: these giant banana nut muffins, these giant almond poppyseed muffins, these giant double chocolate muffins, and these giant blueberry muffins. Pro tip: make all FIVE muffin types and host a fancy giant tea party with all of your vaccinated friends because sometimes it’s just fun and these muffins are down right amazing. Heck, I may be hosting my very own tea party soon because it’s a pretty great idea. AND, if you have ideas for the 6th installment in the series, please let us know by commenting on this post! We need ALL the muffin flavor ideas!!

How do we get that classic Costco size, you might ask? Good question, because Costco seems to have a monopoly on all of the actual Costco-sized muffin trays (if you manage to find them online, tell us please because wow have we searched high and low). So, in lieu of the actual pans, we sub in these 4-inch round cake pans (Costco muffins are 4 inches in diameter, and all “giant” muffin pans out there are a scant 2.75-3 inches, psh), and let me tell you, the resulting muffins are a dream and a half. They essentially are the equivalent of four regular-sized muffins, so pace yourself.

If you’re looking for other breakfasty items to go with these – check out our goat cheese and greens frittata, or these fancy almond waffles with pistachio cream, or these healthy banana pancakes, or these maple glazed baked donuts, or this strawberry snacking bread!

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5 from 1 vote

Giant Glazed Gluten Free Costco Copycat Apple Streusal Muffins

These epic giant Costco copycat apple streusel muffins are the perfect breakfast, complete with vanilla glaze

Prep Time30 minutes mins

Cook Time30 minutes mins

Cooling time10 minutes mins

Course: Breakfast, Dessert, Snack

Cuisine: American

Diet: Gluten Free

Keyword: apple, breakfast, costco muffins, crumb cake, easy, giant, glaze, gluten free, muffins, streusal

Servings: 5 giant muffins

Calories: 550kcal

Author: Amelia Farber

Equipment

• Five 4-inch round cake pans
• Electric mixer
• Cookie sheet

Ingredients

For the streusel topping:

• 5 Tbsp salted butter melted
• 1/4 Cup plus 3 Tbsp gluten free 1-1 flour mix with xanthan gum added (if it doesn't have xanthan gum, add 1/8 teaspoon xanthan gum)
• 1/4 Cup plus 3 Tbsp packed blanched almond flour
• 1 tsp ground cinnamon
• 1/4 Cup packed brown sugar
• pinch salt
• 1/8 tsp vanilla extract

For the muffin batter:

• 3/4 Cup salted butter room temperature
• 1/2 Cup white sugar
• 1/2 Cup packed brown sugar
• 4 large eggs
• 1/4 Cup sour cream
• 1 1/2 tsp vanilla extract
• 1 1/4 Cup gluten free 1-1 flour mix with xanthan gum added (if it doesn't have xanthan gum, add 1 teaspoon xanthan gum)
• 1/2 Cup arrowroot starch
• 1/2 Cup packed blanched almond flour
• 2 1/2 tsp baking powder
• 1/2 tsp salt
• 1/4 tsp ground nutmeg
• 1/8 tsp ground cloves
• 1 1/4 Cup packed peeled grated tart apples about 2-3 medium apples

For the glaze:

• 1 Cup powdered sugar
• 2-4 Tbsp whole milk
• 1 tsp melted salted butter
• 1/2 tsp vanilla extract
• pinch salt

Instructions

• First, make your streusel topping! In a medium bowl, combine all streusel ingredients and stir together with a wooden spoon or spatula until all of the flour has been combined and it's a drier, crumbly mixture. Break crumbs into 1/4-1/2 inch chunks and then let sit while you make the muffin batter.
• Make the muffin batter! In a large bowl, using the electric mixer, cream the butter, white and brown sugar until lighter and fluffy. Add the eggs one at a time, beating the batter in between each addition. Then add the sour cream and vanilla and beat to combine. Then sift in the 1-1 gluten free flour, arrowroot starch, packed blanched almond flour, baking powder and salt and then stir into the batter until fully combined. Finally, peel 2-3 tart apples (I use Granny Smith/green apples), cut in half, and carefully grate them using the large-holed side of your grater (not the tiny holes). Pack all of the grated apple into the 1 1/4 cups and then add to the muffin batter and stir in until fully combined. Let batter rest at room temp for 30 minutes, then bake!
• Once batter has rested, preheat the oven to 425° Fahrenheit, place your five 4-inch round cake pans on a cookie sheet, and grease them with cooking spray or butter. Then scoop batter evenly into the five pans – they should be about 2/3-3/4 full. Finally, crumble the streusel topping on top of the batter generously, then bake for five minutes and then, without opening the oven door, lower the temp to 350° Fahrenheit and bake for 25-30 minutes or until the tops of the muffins spring back with pressed lightly with your fingertip. Let the muffins cool for at least 10-15 minutes before carefully turning them out (gently or the crumb topping will crumble off of the muffin).
• Then make the glaze. In a cereal bowl, combine the powdered sugar, melted butter, vanilla, and 1-2 Tbsp of milk and stir until combined. Continue adding milk and stirring with a spoon until you have an easily-pourable consistency. I just use a small spoon to drizzle the glaze over each muffin. Then serve!

Tag @sisterssansgluten on Instagram if you snap a photo of your muffins!

Food photography and styling by Amelia Farber