1. Preheat the oven to 350°F.
2. Prepare an 8x8 square pan with parchment paper.
3. In a large bowl, add eggs, buttermilk, vegetable oil, sugar, vanilla extract and white vinegar and mix until incorporated. Add flour and baking soda, and mix again until smooth.
4. Pour batter into the prepared pan and bake in the oven for about 15 minutes. Check if the cake is done by inserting a toothpick into it, and if it comes out clean, it is done.
5. Remove from the oven and place on a cooling rack.
6. Slice strawberries and place the strawberries and 1 tablespoon sugar in a bowl and mix.
7. Place in the refrigerator and cover for 1 hour or until ready to serve.
8. After the cake has cooled down, whip the heavy cream and 1 tablespoon of sugar until soft peaks form. Transfer the whipped cream into a piping bag.
9. Layer the trifles by adding a layer of cake, a layer of strawberries, and a layer of whipped cream.
10. Repeat the process and top with a strawberry for garnish, and serve.

Recipe Notes: If you want to get a head start on the strawberries, you may prepare them before you start pre-heating the oven, and place the strawberries and sugar mixture in the refrigerator until you are ready to assemble. To cool the cakes faster, you may use a glass to cut into even circles while the cake is still warm.