In large bowl, whisk together flour, baking soda, baking powder, ginger, lime zest and sea salt. Set aside.
Using hand mixer, beat together softened vegan butter and sugar until well combined and fluffy.
Add milk-vinegar mixture, coconut extract and lime juice; continue beating until well combined.
To make frosting, beat together powdered sugar and vegan butter until it looks ‘peas-like.’ Beat in salt, lime juice and milk until creamy and fluffy. If buttercream is too thin, add additional powdered sugar 1 tablespoon at a time; if too thick, add additional milk 1 tablespoon at a time.