Preheat the oven to 350℉/176℃ and line a muffin pan with parchment liners.
Stir all the wet ingredients (except the cranberries) into a large bowl and let it rest for 5 minutes to curdle the soy milk. (See process shots above for a reference.)
Once curdled, add all the dry ingredients and mix until combined without overmixing. Then fold in the cranberries.
Divide the mixture between your 12 muffin tins and bake for 24-25 minutes, or until a toothpick inserted into the center of a muffin comes out dry. Remove from the oven and let the muffin tray rest for 10 minutes before transferring them to a wire rack.
Notes
Use active/fresh baking powder. Baking powder that has been open for 6+ months may start to lose its effectiveness.
Do not overmix your batter. With most muffin recipes, it's best not to over-mix for optimal texture and fluffiness. When combining wet and dry ingredients, just mix until there are no more floury bits, but don't worry about working out every lump.
Let your muffins cool. They need at least 10 minutes to rest once removed from the oven. Then, transfer them to a cooling rack to continue cooling.
Store leftovers at room temperature for 3-4 days in a sealed container or covered in plastic wrap. Make sure you cover the muffins once cool or they will get dry.Refrigerate for up to 6 days or freeze them airtight for up to 3 months.