For the Cupcakes:
1 cup soymilk (or your favorite non-dairy milk)
1 tsp apple cider vinegar
3/4 cup sugar
1/3 cup vegetable or canola oil
2 teaspoons vanilla
1 1/4 cup all-purpose flour
2 tablespoons cornstarch
1/2 teaspoon baking soda
3/4 teaspoon baking powder
1/2 teaspoon salt

For the frosting:
1/2 cup nonhydrogenated shortening (I used Spectrum Organic)
1/2 cup nonhydrogenated margerine (I used Earth Balance)
3 cups powdered sugar
1 1/2 teaspoons vanilla extract
3-4 tablespoons blackberry puree, strained