First, make the hibiscus syrup. In a small saucepan, combine the water, sugar, and hibiscus powder and cook over medium heat, stirring constantly until all the sugar dissolves. Once the sugar dissolves, let the mixture cook for 5-7 more minutes until thicker. Turn off heat and pour the syrup into a heatproof mug or bowl, then let cool completely (I put mine in the fridge for about 15 minutes).
Next, make your cupcakes - preheat the oven to 350° Fahrenheit and line two cupcake trays with paper liners then set aside. In a large bowl, whisk together the eggs, sour cream, oil, vanilla, strawberry puree, and sugar. Then, add in the flour mix, almond flour, baking powder, baking soda, salt, and hibiscus powder, and whisk to combine. Add in the red food coloring if using (to your color liking), then spoon the batter into the lined cupcake pans (each cup should be about 3/4 full). Bake for 20-25 minutes or until a skewer inserted into the center of a cupcake comes out clean. Let cool completely before frosting.
While the cupcakes are cooling, make the buttercream. In another large bowl, using an electric hand or stand mixer, beat together the room temp butter and cream cheese until smooth. Add in 1 cup of powdered sugar at a time until thicker and smooth. Then, in a food processor or nutribullet, blitz up 1-2 packages of freeze dried strawberries until you get a fine powder. Sift the powder to remove seeds and add about 1/3 cup of it to your frosting mixture (all up to your taste - add more or less if you want!). Then, add in the hibiscus syrup, pureed strawberries, and vanilla and beat until smooth. Add more powdered sugar if the frosting doesn't hold its shape/is too loose, or add more strawberry puree or syrup if it's too stiff to pipe. Add red food coloring if using to your desired hue. Then, scoop buttercream into a piping bag and pipe onto cooled cupcakes. Then serve!