Whisk flour. baking powder and salt in a bowl, set aside

Beat egg yolks and buttermilk until light in color and increased in volume. Beat in 1 cup of the sugar and vanilla until well mixed

Stir in flour mixture. Making sure it's mixed well but don't overmix

With clean and dry beaters beat egg whites and cream of tarter until soft peaks form, slowly add remaing 1/2 cup sugar and beat until glossy peaks form

Fold 1/4 of egg whites into egg yolk mixture then fold in remaining in 3 more additions.

Spread batter evenly in prepared pan.Bake 16 to 18 minutes until golden and not sticky to touch and it springs back when touched

Cool 5 minutes on rack in pan. Run a knife around edges of cake to unstick any edges if cake

After cake cools 5 minutes invert onto confectioners sugar dusted kitchen towel. Carefully peel off parchment paper

Roll cake up in towel, into a roll. Cool in towel on rack

Beat cream until soft peaks form, add strawberry jan, confectioner's sugar and vanilla and beat until stiff peaks form. Add drops of food color now if you want a darker pink color.

Unroll cooled cake and spread strawberry cream over cake

Roll cake up, using towel as a guide to tightly roll. Place seam side down on pan and frost withe Creamy Buttcream Frosting recipe attached below, and decorate with sprinkles, strawberries and blueberries. Cake should be stored in refigerator

https://cookpad.wasmer.app/us/recipes/367337-basic-creamy-vanilla-buttercream-frosting