Preheat oven to 375°F. Line 12-cup muffin pan with greaseproof cupcake liners. (I used Shop Sweets and Treats.) Set aside.

In a medium size bowl, whisk together all of the dry ingredients except sugar. Set aside.

In a large bowl, stir together the wet ingredients, plus sugar. Whisk in dry ingredients and keep stirring until completely combined and smooth.

Scoop batter into prepared muffin cups using an ice cream scoop or spoon. Bake for 18-20 minutes or until a toothpick inserted in center of cupcake comes out clean. Let cool completely.

To fill, use the bottom of a #826 pastry tip to press down in the middle of each cooled cupcake. Press down about ½-inch, then lift out. Carefully remove the small piece of cupcake from the pastry tip and set aside. Scoop about ½ teaspoon of Sunbutter into the cupcake. Replace the piece you removed. Repeat for all 12 cupcakes.

Meanwhile, prepare the buttercream. Measure water and vanilla in a small measuring cup. Set aside. Place shortening in a large bowl and beat with an electric mixer on medium high for 1 minute. Add Sunbutter and beat until incorporated. With the mixer on low, gradually add the powdered sugar and water/vanilla mixture. Once all is combined, turn mixer up to medium high and beat for 2 minutes. If it's too thick, you can add a little more water, but not too much. Maybe 1-2 tablespoons.

Scoop icing into a large pastry bag fitted with a #826 or #1M pastry tip (they are similar). Pipe frosting onto cooled cupcakes.

Garnish with chocolate covered sunflower seeds, if desired. Store covered in refrigerator for up 5 days.