Mix the plant-based milk with vinegar and set aside.
Preheat the oven to 360°F.
Beat the fine sugar and butter in a container until dissolved and soft. Add half the milk and beat for a few seconds. Then add flour, baking powder, orange zest and keep beating. Lastly add the rest of the milk.
Pour into a previously greased and floured baking pan and bake for about 40 minutes or until the sponge is brown on top.
Blend the orange juice and physalis, strain the mixture and pour the liquid into a pot.
Add 4.9 oz sugar and bring to a boil over medium-high heat. Allow to boil for 8 minutes and remove from the heat.
Unmold the sponge cake and dock using a skewer stick. Pour the orange and physalis syrup over the cake.
Wait until completely cooled before serving.
