Prepare muffin tin by placing 12 standard muffin papers in the muffin pan then adding 12 tulip paper liners on top of the standard paper liners. Placing the muffin papers in first will add an extra layer of protection to prevent the bottom and sides of the muffin from baking up too dark, which usually happens with banana bread and muffins.

Spray the inside of the tulip papers with kitchen pan spray and set aside.

Preheat oven to 325 degrees F. with rack in the upper half of the oven.

In the bowl of a stand mixer with the paddle attachment, beat the eggs on a high speed for five full minutes to incorporate air into the batter.

Add the brown sugar and vanilla and beat for two more minutes on medium speed.

Add the mashed bananas and beat for two more minutes on medium speed.

In a separate bowl, sift the flour, baking soda, baking powder and chai spice.

With the mixer running on low, add the sea salt then slowly add the flour mixture and mix until no dry shows.

Scrape the bowl and beat again.

Add butter and beat on medium until incorporated and fluffy. Scrape and beat again.

Use a large ice cream scoop and divide the batter between the 12 prepared tulip cups.

In a bowl, mix all of the streusel topping and divide evenly over the top of each muffin. I found it easier to use a sturdy whisk to mix the topping.

Bake for 35 minutes.

Insert a toothpick into the center of one muffin and if it comes out clean, remove the muffins from the oven. If there is still wet batter on the toothpick, bake for a minute or two longer until a toothpick comes out clean. Do not over bake.

Serve warm with butter.

Store leftovers at room temperature covered tightly for up to two days, or wrap tightly with plastic and freeze until needed.