Combine the flour, baking soda, baking powder and salt in a medium bowl. Whisk and set aside. In another bowl, whisk together the cocoa powder and hot water until smooth.
Puree the strawberries in a food processor. Strain the puree through a fine mesh sieve placed over a bowl to remove the seeds. Add butter to the clean bowl of a stand mixer fitted with the paddle attachment. Beat on medium speed for 30 seconds. Add the confectioners’ sugar and mix until light and fluffy, about 4 minutes. Add marshmallow fluff and salt; beat for an additional minute. Add strawberry puree, a tablespoon at a time, until desired color and flavor is reached. Beat on high for about 30 seconds to lighten the frosting.
*Nutritional information is an estimate. Please consult a doctor or nutritionist for the most accurate nutritional info.