Preheat the oven to 350°F (177°C). Line a 12-cup muffin pan with cupcake liners. Line a second pan (or bake in batches) with 6 liners—this recipe makes about 18 cupcakes. Set aside.

Whisk the flour, baking soda, baking powder, cinnamon, and salt together. Set aside.

Using a handheld or stand mixer fitted with a paddle attachment, beat the butter, brown sugar, and granulated sugar on medium-high speed until creamed together, about 3 minutes. (Here’s a helpful tutorial if you need guidance on how to cream butter and sugar.) Scrape down the sides and bottom of the bowl with a silicone spatula as needed. Add the eggs, sour cream/yogurt, and vanilla extract, then beat on medium-high speed until combined. Scrape down the sides and bottom of the bowl as needed. Beat in the mashed banana. (Buttermilk is in the next step.)

With the mixer on low speed, add the dry ingredients until just incorporated. With the mixer still running on low, slowly pour in the buttermilk until combined. Do not overmix. You may need to whisk it all by hand to make sure there are no dry flour pockets at the bottom of the bowl.

Pour/spoon the batter into the liners—fill only 2/3 full to avoid spilling over the sides. Bake for 18–20 minutes, or until a toothpick inserted in the center comes out clean. For about 36 mini cupcakes, bake for about 11–13 minutes, same oven temperature.

Cool the cupcakes in the pan set on a cooling rack for 20 minutes, then remove them from the pan and return to the rack to cool completely before frosting.

In a large bowl using a handheld or stand mixer fitted with a paddle or whisk attachment, beat the cream cheese and butter together on high speed until smooth and creamy. Add 3 cups (360g) confectioners’ sugar, the vanilla, cinnamon, and salt. Beat on low speed for 30 seconds, then gradually increase the speed to high and beat for 2 minutes. If you want the frosting a little thicker, add the extra 1/4 cup of confectioners sugar (I usually add it).

If desired, to help ensure the frosting holds piped shape, refrigerate the bowl of frosting for at least 20 minutes. Frost cooled cupcakes. For the pictured cupcakes, I used piping tip Ateco #826. I also like Ateco #808 piping tip for cream cheese frosting. Instead, you can skip the piping tips and use a knife or icing spatula to spread on the frosting. Garnish with banana slices and crushed Nilla Wafer cookies, if desired.

Cover leftover cupcakes tightly and store in the refrigerator for up to 3 days. I recommend a cupcake carrier for storing and transporting decorated cupcakes.