Preheat the oven to 175 degrees Celsius. Line 12 6 cupcake moulds with cupcake liners. Set aside. Combine the flour, baking soda and baking powder in a small bowl and set aside.
Place the unsalted butter and sugar in a large mixing bowl. Using an electric mixer, beat on high speed until the mixture is light and fluffy, about 5 minutes.
Add in the egg and vanilla extract and beat on medium speed for 1 minute until incorporated. Add in the mashed strawberries and beat on low speed to incorporate them. Drizzle in the milk slowly, beating well on low speed.
Sift in the flour mixture in two parts and fold it in gently. Add in red food colouring if desired.
Divide the cake batter (1/4-cup batter per cupcake) and bake the cupcakes for 12-15 minutes, until a skewer inserted into the center of the cake comes out clean. Let the cupcakes cool on a wire rack completely before frosting.
Frosting 1 - Cooked Flour Frosting
Whisk the flour and milk together in a small pot. Heat the milk mixture over medium heat and whisk consistently until it has thickened into a glue-like consistency. Remove from heat and let cool completely. To speed up the process, place the pot over a ice water bath to let it cool faster.
In a mixing bowl, combine the butter and superfine sugar. Beat with an electric mixer until light and fluffy. Add in the cooled milk mixture and the dried strawberry powder. Beat with the electric mixer until thoroughly combined. Use as desired.
See the step-by-step photos on how to make the frosting here.
Frosting 2 - Cream Cheese Frosting
Place the cream cheese and the unsalted butter in a large bowl. Using an electric mixer, beat the cream cheese and butter until creamy, for 1 minute. Add in 125 grams of icing sugar (1 cup) and beat until fully incorporated.
Add in the mashed and drained strawberries and lemon juice and beat on low speed to incorporate. Beat in the remaining icing sugar until you've obtained your desired sweetness and consistency.