Preheat the oven to 325F. Grease a 8 x 8 inches baking dish and line it with parchment paper.

Melt the butter and put it aside. Let it cool a bit.

Whip the egg whites with salt to stiff peaks. Set aside.

In a separate bowl, beat the egg yolks with sugar and vanilla extract. Add in melted butter and beat until creamy, about 1-2 minutes.

Combine rice flour and cocoa powder in another bowl and sift it into the batter. Mix with a spatula until combined well. Gradually add in the milk and mix well.

Fold in the egg whites in 3 or 4 parts stirring gently until no big chunks left. Don’t overmix.

Pour the batter into the baking dish and bake for 60 minutes.

Let it cool down and chill at least for an hour before slicing.

Top with strawberries when serving.