1 ½cups(about 340 g)mashed ripe bananas, about 3 large bananas (see note)
1cup(170g)mini chocolate chips or regular chocolate chips
Preheat the oven to 350 degrees F (make sure an oven rack is in the middle position). Grease an 8X8- or 9X9-inch baking pan with cooking spray. See note below for pan type (metal vs. glass).
In a medium bowl, whisk together the flour, salt and baking soda.
In a large bowl with a handheld electric mixer or in the bowl of a stand mixer fitted with the paddle attachment, cream together the butter and sugar until light and fluffy, 2-3 minutes, scraping down the sides of the bowl as needed.
Add the eggs and mix to combine.
Add the bananas and vanilla and mix.
Add 1/3 of the flour mixture and mix until a few dry streaks remain. Add 1/2 of the buttermilk and mix. Add another 1/3 of the flour and mix again, followed by the remaining buttermilk. Finally add the last of the flour AND the chocolate chips and mix until just combined (don't overmix!).
Spread the batter evenly in the prepared pan and bake for 45-55 minutes until a toothpick inserted in the center comes out clean. Let the cake cool completely in the pan (or dig in while warm; no judging).
Whole Wheat Flour: I always use the white whole wheat variety when baking with whole wheat flour (it's a bit lighter in color and texture). Also, you can definitely experiment subbing in whole wheat flour for the cup of all-purpose flour. I liked the ratio of half whole wheat/half all-purpose flour so that the cake wasn't overly dense. You'll also notice I'm using slightly less ounces for the cup of whole wheat flour than I am for the all-purpose flour. If you don't have a scale, just measure with a light hand so the whole wheat isn't packed into the measuring cup (that will make for a heavy, overly dense cake).Bananas: make sure the bananas you use are speckled with brown spots - the more speckles, the sweeter the bananas will be! If the bananas aren't ripe enough, the cake won't have the same delicious banana flavor and natural sweetness. Pans: I always use metal baking pans for recipes like this. You could try baking in a glass pan - just keep in mind that you may want to bake at 325 degrees instead of 350 (a common adjustment with glass pans), and I'm not sure the sides of a glass pan will be high enough for this cake. It makes a fairly thick cake, so regardless of the pan you use, make sure the sides are at least 2 1/2 inches high (or use a larger baking pan).