Preheat oven to 400 F (204 C). Line a standard cupcake/ muffin pan with muffin liners.
Make the streusel topping:
Whisk together the flour, sugar, oats, and salt. Add in the butter next and mix until coarse crumbs form. Set aside.
Make the filling:
Mix the room temperature cream cheese, sugar, and vanilla in a small bowl. Set aside.
Make the batter:
In a bowl, combine the pumpkin, eggs, brown sugar, oil, honey, salt, pumpkin spice, baking powder, baking soda, and milk using a whisk. Be sure to scrape down the sides and bottom of the bowl with a spatula.
Add the flour and continue whisking until combined. Scrape down the sides and bottom of the bowl again and beat briefly to incorporate everything.
Drop about 2 tablespoons of the batter (a heaping tablespoon cookie scoop works well here) into each muffin cup, spreading it to cover the bottom. Dollop on a heaping tablespoon of filling, then cover with another 2 tablespoons of batter. Sprinkle each muffin with some of the streusel topping.
Baking and Cooling:
Bake the muffins for 18 to 20 minutes, until a cake tester inserted towards the edge (not into the filling) comes out crumb-free.
Remove the muffins from the oven. As soon as they're cool enough handle, transfer them to a rack to cool completely.
(Note 1) For accuracy, weigh ingredients instead of using cups.(Note 2) To make this as mini muffins, bake at 375 F (190 C) for 12-15 minutes. Yields 24 mini muffins.(Note 3) Refrigerate up to 3 days for longer storage. Freeze, well-wrapped, up to 3 weeks.(Note 4) Rewarm cold muffins in a preheated 350°F oven, tented with foil.Or heat briefly in a microwave set at low power (I use defrost function, 1 min 30 seconds if muffin is from fridge).