Apple Cinnamon Crumb Muffins

Source: Sally's Baking Addiction, via Megan

Ingredients:
for the crumb topping:
1/3 cup (67g) light or dark brown sugar (I used light)
1 Tablespoon (15g) granulated sugar
1 teaspoon ground cinnamon
1/4 cup (60g) unsalted butter, melted (I used salted)
2/3 cup (84g) all-purpose flour

for the muffins:
1/2 cup (115g) unsalted butter, softened to room temperature (I used salted)
1/2 cup (100g) light or dark sugar (I used light)
1/4 cup (50g) granulated sugar
2 large eggs, room temperature preferred (mine were straight from the fridge)
1/2 cup (120g) yogurt (I used plain, but you can use any flavor or sour cream is a good substitute)
2 teaspoons vanilla extract
1 and 3/4 cups (220g) all-purpose flour (Meg said she used 1 cup whole wheat + 3/4 all purpose, so I did, too)
1 teaspoon baking soda (I'm pretty sure I forgot this now that I'm looking at it - they rose just fine!)
1 teaspoon baking powder
1 teaspoon ground cinnamon
1/2 teaspoon salt
1/4 cup (60ml) milk (any kind)
1 and 1/2 cups peeled, chopped apple (2 small apples) (I used one fairly large fuji and I didn't peel mine)

for the glaze: (neither Megan or I made the glaze - I thought they were plenty sweet and delicious (and messy!))
1 cup (120g) confectioners' sugar
3 Tablespoons (45ml) heavy cream (or milk for a less creamy texture)
1/2 teaspoon vanilla extract

Directions:
First, make the crumb topping. In a medium bowl, combine both sugars, the cinnamon, and melted butter. Using a rubber spatula, stir in the flour. The crumb topping will be thick and crumbly. Set aside.

Preheat oven to 425F degrees. Spray a jumbo muffin pan with nonstick spray. (I used a regular 12-cup muffin pan lined with paper liners, and it ended up making 13 muffins.)

Make the muffins: In a medium bowl using a handheld or stand mixer fitted with a paddle attachment, beat the butter on high speed until smooth and creamy, about 1 minute. Add the brown sugar and granulated sugar and beat on high until creamed, about 2 full minutes. Scrape down the sides and bottom of the bowl as needed. Add the eggs, yogurt, and vanilla extract. Beat on medium speed for 1 minute, then turn up to high speed until the mixture is combined and uniform in texture. Scrape down the sides and bottom of the bowl as needed.

In a large bowl, toss together the flour, baking soda, baking powder, cinnamon, and salt. Pour the wet ingredients into the dry ingredients and slowly mix with a whisk. Add the milk, gently whisking until combined and little lumps remain. Fold in the apples with a wooden spoon or rubber spatula.

Spoon the muffin batter evenly between all 6 muffin tins. There may be enough to make a 7th muffin in a 2nd batch, depending if there were a few extra apple chunks thrown in. Fill the muffin tins until they are full all the way up to the top. Press a handful of the crumb topping into the top of each; crumble it with your hands to make some big chunks.
Bake for 5 minutes at 425F degrees, then keeping the muffins in the oven, lower the oven temperature to 350F degrees and bake for 21-23 more minutes or until a toothpick inserted in the center comes out clean. The total time these jumbo muffins take in the oven is about 26-28 minutes.  (For the regular muffins, I did 5 minutes at 425F and then 14 at 350F - but I should have checked them even earlier than that - I think they were almost too done.)

Make the glaze: whisk all of the ingredients together and drizzle over warm muffins. Muffins stay soft, fresh, and moist at room temperature for up to 5 days. Unglazed muffins freeze well, up to 3 months.

Notes:
While Skyping recently with my mom, Cal and I saw Mugs in the background making muffins.  She shared the recipe with me and I made them the next day for my November Muffin of the Month.  These were mighty tasty fresh, but I think they actually improved overnight because they were even more moist in the morning.  I love the big chunks of apple and the crumbly top.  (But don't make these if you hate crumbs - they are definitely not a "clean eating" muffin!)