Preheat oven to 350 degrees.
In one bowl, sift together the flour, baking soda, baking powder, cinnamon, nutmeg, ginger, cardamom, and salt. In another bowl, mix together the pumpkin puree, honey, sugar, butter, and eggs. Now mix the dry ingredients into the wet ones until combined. Stir in the crushed walnuts.
Line 12 muffin molds with muffin wrappers and grease 12 donut molds. Use a piping bag (or ziplock with a hold cut in the corner) to fill up each muffin wrapper and each donut mold to about 75% capacity. Place in oven for 25-30 minutes or until a toothpick comes out clean.
Meanwhile, prepare cream cheese frosting by using a hand mixer to blend together the cream cheese, butter, cinnamon, and chai concentrate. Slowly incorporate the powdered sugar, cup-by-cup, until combined. Now place this bowl in fridge until ready to use.
Once the muffins and donuts are cooked, remove them from the molds and let them cool on a cooling rack. When they have reached room temperature, use a piping bag with an attachment to top each muffin/donut with the frosting. Finally, dust with some extra cinnamon.