Grease a 10-inch tube pan with non-stick spray, focusing on the removable bottom. Dust with flour, tapping out excess.
Whip egg whites on medium speed until soft peaks form. Gradually add 1 tbsp sugar, then increase speed until stiff peaks form (60-90 seconds).
Sift flour and baking powder together twice in a large mixing bowl.
Gently fold the dry mixture into egg whites in 3 batches. The batter should fall smoothly from the spatula, showing faint streaks.
Pour the batter into the prepared pan and bake at 350°F (175°C) for 35-40 minutes until golden and springy to the touch.
Cool the cake in the pan for 1 hour, then invert and let cool completely.
Whip cream with 2 tbsp sugar and 1 tbsp vanilla extract to desired consistency.
Slice the cooled cake horizontally into 2-3 layers. Alternate layers of cake with strawberries and whipped cream. Chill for 2 hours before serving.