1. Preheat oven to 375°F.
2. Butter and flour an 8-or 9-inch square cake pan, cut a piece of parchment paper and line bottom of pan and set aside. Sift together flour and baking powder and set aside.
3. Separate eggs. Make sure no egg yolk enters egg whites, as egg whites do not whip when traces of yolk are present.
4. In bowl whip egg yolks for a minute. Add 2 tablespoons sugar and whip until mixture is light in color and makes thick ribbons, about 10 minutes. Add salt and vanilla. Set aside.
5. In separate bowl whip egg whites, 3 tablespoons sugar, and cream of tartar on medium speed to soft medium peaks. Using a hand held spatula fold whipped egg whites into whipped egg yolk mixture. Do not overfold to prevent mixture from collapsing.
6. Add half of flour and gently fold until incorporated; add remaining flour and combine ensuring a light mixture. Scrape in pan and place in oven.
7. Bake until an inserted toothpick comes out clean, about 15-20 minutes. Turn upside down and place on a sheet of parchment paper, paper towel, or kitchen towel.
8. Meanwhile make syrup by boiling water and sugar. Remove from heat and chill on ice. Once cooled add liquor.
9. Slice cooled cake horizontally in half. Using a round cutter, cut circles that will fit snugly on the bottom of your glasses.
10. Place cake circles into glasses and spoon a generous tablespoon of syrup in each glass.
11. Remove stems from strawberries and stand point up. Cut right in the center 1/8-inch-thick slices. The smaller sides of the strawberries will be used on the inside of the dessert, which will not be visible. Only obtain nice large slices.
12. Press large strawberry slices on the sides of the glass into a row. Continue with all glasses.
13. Place smaller strawberry pieces in center of glass onto cake.
14. In a cold bowl whip heavy cream, sugar, and vanilla extract until it makes soft peaks. Do not whip until firm peaks form.
15. Spoon 2 tablespoons whipped cream into the glass covering strawberry pieces.
16. Fit another piece of cake into the glass and moisten it with a generous tablespoon of syrup.
17. Spoon about 3-4 tablespoons of whipped cream into the glass and top with a layer of blueberries.
18. Cover with raspberries and keep refrigerated until ready to serve.