For the cake:

1. Preheat oven to 350 degrees, line a muffin tin with cupcake liners.
2. Whisk flour, salt, cardamom, and baking powder together in a large bowl.
3. Cream butter and sugar together in a stand mixer until light and fluffy. About 3 minutes. 
4. Add the eggs one at a time beating completely before adding the next egg.
5. Mix milk and vanilla together and while the mixer is on low add 1/3 of the flour mixture followed by 1/3 of the milk, keep alternating wet and dry ingredients until all are incorporated.
6.  Pour in the strawberries and mix to combine.
7. Divide the mixture evenly between the cupcake liners. Bake for 20-25 minutes or until the tops of the cupcakes spring back when gently touched and a toothpick inserted in the center comes out clean. Allow to cool in the pan for 5 minutes, then transfer to a rack to cool completely.

For the buttercream:

1. Put eggs whites and sugar in a heatproof bowl set over a pot of simmering water. Whisk until sugar is completely dissolved and mixture reaches 160 degrees. 
2. Remove bowl from heat and attach the bowl to a mixer, whisk on medium-high speed for 5 minutes or until very stiff peaks form. Lower speed to medium and start adding butter one piece at a time until are all combined. Add in the chopped basil. Whisk until stiff peaks form again if you lost definition when adding the butter. 
3. Switch to the paddle attachment and on low speed slowly add a little bit of the strawberries, keep mixing and adding strawberries until all are combined. Whisk on medium speed to firm up the mixture. 
4. Frost the cupcakes and garnish with leftover strawberry puree and rose petals.