In a large mixing bowl, combine flour, baking soda, and baking powder.
In a separate bowl, combine the rest of the ingredients except for the walnuts.
Pour wet ingredients into the dry ingredients. Mix well.
Fold in the walnuts.
Scoop batter into 12 cup muffin tin evenly.
Bake for 15-18 minutes or until a toothpick comes out clean.
Optionally, top with cream cheese frosting. Make the frosting by combining room temperature cream cheese with 1/2 cup of maple syrup and 1 tsp vanilla extract. Mix with an immersion blender until creamed.
Notes
Store in airtight container in fridge for 3-4 days.Freeze in freezer safe bag for up to 3 months.