Preheat your oven to 180 C.

Grease a 6 inch round pan with butter and dust with flour. Line the bottom with parchment. Whisk together the flour, salt and baking powder in a bowl. Keep aside.

Beat together the butter and sugar until light , fluffy and creamy.

Beat in the egg whites until fully incorporated.

Beat in the vanilla extract.

Now add in the flour in 3 additions and the milk in 2 additions, and beat after each addition. so, 1/3rd of the flour mixture -beat- 1/2 of the milk- beat - 1/3rd of flour - beat -remaining milk - beat - remaining 1/3 of flour mixture- Beat. Scrape your bowl as needed.

Pour batter into the prepared pan and smooth the top.Bake at 160 C/325 F for 42 to 50 minutes until the cake springs back when touched or a toothpick inserted in the center comes out clean.

Cool in pan for 5 minutes and then invert onto a cooling rack to cool completely.

Sprinkle gelatin all over the strawberry purée. Set aside for at least 5 minutes.

Whisk egg yolks and sugar in a small mixing bowl until pale and thick. Set aside.

Place the milk in a saucepan and bring to a simmer ( small bubbles begin to appear on the edges).

Add a little of the milk into the egg yolk mixture while whisking . This is called tempering. Add some more while whisking in the same way. Continue until all the milk is mixed with the yolks.

Now , pour the egg yolks and milk mixture into the saucepan.

Continue cooking on medium-low heat, stirring constantly with a wooden spoon or spatula until thickened.

Now take the saucepan off heat and stir in the strawberry-gelatin mix.

If gelatin hasnt dissolved completely , you can heat the saucepan on low while stirring.

Strain the mixture and stir in the lime juice

Let the mixture cool to room temperature.

Whip the cream until medium stiff peaks formed.

Whisk in ⅓ of the cream into the strawberry mixture to lighten it, then fold in the remaining whipped cream.

Slice the cooled cake horizontally into 3 layers. Line your cake tin with plastic wrap so that it is above the edges of the pan (to pull out later ). If using a springiform / loose bottomed pan , just line the bottom with parchment. You can skip this and just assemble like you would a regular cake.

Place a layer of cake on your serving plate / cake tin.

Spread about a 1/3 of the cream filling.

Place the second layer on top, press gently. Layer with cream .

Place last layer on top and press gently. Spread a little cream on top and smoothen.

If assembling on a plate , spread some on the sides of the cake and smoothen.

Chill for atleast 4 hours . Remove from pan and decorate as needed.

Serve after bringing to room temperature (half hour out of the fridge)