Begin by preheating your oven to 350 degrees and spraying a donut pan with cooking spray. Set aside.

In a bowl, sift together flour, baking powder, baking soda, salt and ground cinnamon. Set aside.

In a separate bowl, whisk together egg and brown sugar.

Add milk and Greek yogurt and combine, followed by the melted butter.

Once all wet ingredients are thoroughly combined, add blue gel food coloring and stir until wet ingredients are completely tinted.

Next, slowly add dry ingredients into wet ingredients and fold until well combined. The batter will be thick.

Insert batter into a piping bag, and pipe into each section of your donut tin.

Bake for 8 to 10 minutes or until a toothpick comes out clean when inserted in the center.

Allow to cool for 5 minutes and remove from pan. Place on a wire rack and allow to cool down completely before decorating.

Once the donuts are cooled, prepare your buttercream. Use an electric mixer to beat together softened butter, powdered sugar and milk. If your buttercream is too runny, add more powdered sugar, one tablespoon at a time. If it’s too thick, add more milk one tablespoon at a time.

Your buttercream is ready once it forms semi-stiff peaks.

Scoop the buttercream into a piping bag with a round tip attachment and frost an arch at the top of each donut.

Next, add your candy-covered chocolates along this arch, giving it the look of a rainbow.

Finally, pipe some buttercream clouds at the ends of your rainbow. Serve and enjoy!