Preheat oven to 350 degrees F. Line 12 (1/2-cup) muffin cups with paper liners.
Whisk whole-wheat flour, all-purpose flour, baking powder and salt in a medium bowl.
Beat granulated sugar and coconut oil (or butter) in a large mixing bowl with an electric mixer on medium speed until creamy. Add eggs, 2 teaspoons lemon zest and vanilla; beat until combined. With the mixer on low, alternately mix in the dry ingredients and milk, starting and ending with dry ingredients and scraping the sides of the bowl as needed, until just combined. Fold in strawberries. Divide the batter among the prepared cups.
Bake the cupcakes until a toothpick inserted into the center comes out clean, 18 to 25 minutes. Transfer to a wire rack and let cool completely.
Meanwhile, combine cream cheese, confectioners' sugar, lemon juice, the remaining 2 teaspoons lemon zest and food coloring, if using, in a mixing bowl. Beat with an electric mixer until smooth. Refrigerate until cold, about 1 hour.
Frost each cupcake with a generous tablespoon of the cream cheese frosting and top with a mint leaf and lemon slice, if desired.
Equipment: Muffin tin with 12 (1/2-cup) cups, paper liners
2 1/2 fat, 1 other carbohydrate, 1/2 starch