Whisk together flour(s), chia seeds, baking powder, baking soda, and salt. Set aside.
Add butter and both sugars to a medium bowl. With a hand or stand mixer, beat on medium until light and fluffy, about two to three minutes. In that time, spatula the sides down a couple times. Add both eggs and almond extract then begin on low this time and mix just until incorporated but smooth.
With your mixer still on low, add the flour in two batches, mixing just until almost incorporated after each. Now switch to a spatula: fold the mashed banana and chocolate into the batter; reach bottom of the bowl to top, making sure flour isn't hiding below.
Spatula the batter into the prepared pan. Use a knife or offset spatula to even the top, then sprinkle with more chopped chocolate.
Bake on the center rack for 40-50 minutes.Begin checking five minutes prior to the earliest finish time. Bake until the bread's just set and a center toothpick comes out with few to no crumbs. It's better for the bread to be underdone and continue baking on the rack, then overdone.
Remove pan from the oven and let stand on the cooktop for 10 minutes. Then remove (with parchment in place) and transfer to a wire rack. Enjoy warm or cooled.
Notes
The coconut sugar adds complexity, but the bread doesn't taste like coconut.
All-purpose flour can be used in place of whole wheat flour(s) but changes the consistency and nutrition.
I prefer this bread moist the whole way through, so store in an airtight container.
Bread keeps for up to four days but is best the second day.