Preheat oven to 375 degrees F. Lightly grease and flour a 2-quart casserole dish.
In a large bowl, beat egg whites until frothy; gradually add 4 tablespoons of the sugar and continue beating on high speed until they form peaks with tips that stand straight when the beaters are lifted.
In a separate bowl, beat the egg yolks with the remaining sugar until they are a creamy lemon color. Fold the yolk mixture into the beaten whites until just blended.
In a medium bowl, sift together flour, baking powder, and salt. Gently fold in the flour mixture into the egg mixture. Gently drizzle in the melted butter and vanilla. Pour into prepared baking dish and bake for approximately 30 minutes or until lightly browned on top; remove from oven.
While the cake is baking, prepare the Rum Sauce.
When the cake is done baking, make holes all over the top of the warm torte with an ice pick or skewer and pour the Rum Sauce over it. Before the Rum Sauce is all absorbed into the cake, sprinkle generously with chopped nuts or grated coconut (if desired)./
In a large saucepan over medium-high heat, boil the water and sugar until the cooking thermometer reaches 235 degrees F. or until it forms a soft ball when a little of the mixture is dropped in cold water.
Remove from heat and stir in whatever liquor you are using; pour over the top of the warm cake.
Torta Borracha Recipe: https://whatscookingamerica.net/cynthiapineda/tortaborracha.htm