Grease and flour a 13x9x2-inch baking pan. Line the bottom of pan with waxed paper; set aside. In small bowl stir together flour, baking powder, and salt; set aside.
Preheat oven to 350 degrees F. In a medium mixing bowl beat eggs with an electric mixer on high speed about 4 minutes or until thick. Gradually add sugar, beating on medium speed 4 to 5 minutes or until light and fluffy. Add flour mixture; beat on low to medium speed just until combined.
In a small saucepan heat and stir milk and butter until butter melts. Add to batter along with the vanilla paste; beat until combined. Pour batter into prepared pan.
Bake 30 to 35 minutes or until a wooden toothpick inserted near center comes out clean. Cool cake in pan on a wire rack for 15 minutes. Remove cake from pan; peel off waxed paper. Place cake on a baking sheet. Cover with plastic wrap; cool completely.
In a chilled bowl beat whipping cream with an electric mixer on medium speed until soft peaks form. Gradually add 1/3 cup of the jelly. Beat until combined; set aside.
Using a serrated knife, trim cake edges to create straight sides. Cut cake lengthwise in half. Cut each half into seven 4 1/4 x 1 3/4- inch pieces. (You should have 14 mini cakes.) Split cakes horizontally into 3 layers. For each individual cake, spread a thin layer of jelly on the bottom cake layer; top with 1 Tbsp. whipped cream mixture. Add second cake layer; repeat jelly and whipped cream steps. Finish with top cake layer. Sprinkle with powdered sugar.