DOUGH: In a large mixing bowl, heat the almond milk and vegan butter in the microwave in 30 sec increments (or heat over medium heat in a large sauce pan), until warm and melted (never reaching boiling). Let cool to 110 degrees (43 C) - the temperature of bath water. It should be warm but not too hot or it will kill the yeast. (If you used a saucepan to heat the milk, transfer to a large mixing bowl now.)
Sprinkle on yeast and let activate for 10 minutes. Then add sugar and salt and stir. Next, add in mashed ripe banana and stir. Add flour 1/2 cup at a time, stirring as you go. The dough will be sticky. When it is too thick to stir, transfer to a lightly floured surface and knead for a minute or so, adding flour as needed, until it forms a loose but still springy ball. Only use as much flour as it will take.
Rinse out your mixing bowl, coat it with avocado or olive oil, and add your dough ball back in seam side down. Cover with plastic wrap and set in a warm place to rise for about 1 hour, or until doubled in size (see photo) - mine only took 40 minutes.
FILLING: On a lightly floured surface, roll out the dough into a long rectangle ~1/4 inch thick. Brush with melted vegan butter and top with cane sugar (I used a little brown sugar mixed in with the cane sugar) and 1/2 - 1 Tbsp cinnamon (up to preference // amount as original recipe is written // adjust if altering batch size). Then add banana slices so it's easy to roll, and walnuts.
Slowly and tightly roll up the dough and situate seam side down. With a serrated knife or a string of floss, cut the dough into 1 1/2 - 2 inch sections and position in a well-buttered 8x8 square or comparable sized round pan (you should have about 10 rolls as original recipe is written).
TOPPING: Brush with melted vegan butter and sprinkle with sugar (brown or cane) and remaining walnuts.
Cinnamon rolls should keep covered at room temp for up to a few days, though best when fresh. You can freeze at the stage where the dough is cut into cinnamon rolls and placed in a pan. Cover well and freeze in a pan, then let thaw for at least 6 hours before baking. Cover and set on top of the oven while preheating to help rise. Bake as instructed.
*For a simple dairy-free glaze, melt (as recipe is written // adjust if altering batch size) 1 Tbsp vegan butter and add to ~2 - 2 1/2 cups powdered sugar. Mix and gradually thin with dairy-free milk 1 tsp at a time until pourable but still thick.
*Nutrition information is a rough estimate calculated without glaze.
*Adapted from my World's Easiest Cinnamon Rolls.