Step 1Preheat oven to 350°.
Step 2In medium bowl, mix flour, cocoa, baking soda, baking powder and salt. In large bowl with an electric mixer, beat vegan buttery stick and sugar until mixed; beat in almond milk. Slowly add half of the flour mixture and then add soy yogurt. Add remaining flour mixture. The batter will be very thick like a frosting.
Step 3Line baking sheets with parchment paper; use a small melon baller to drop batter onto baking sheets, spaced about 2-inches apart. Bake for 6-8 minutes, depending on size of cakes, being careful not to burn the bottoms. Transfer to wire racks to cool.
Step 4For filling, beat ingredients until fluffy. Add more sugar if you want a thicker filling.
Step 5Spread generous amount of filling between the cooled cakes. Makes 2 dozen mini whoppie pies.