In a small mixing bowl, add the egg white, sugar, vanilla and lemon zest, whisk until combined. Add in the melted butter and stir until mixed. Add the cake flour, baking powder and salt to a medium sieve, place over the bowl and tap over the bowl. Once all of the dry ingredients have been "sifted" into the bowl, stir until smooth. Stir in the milk. Pour the batter into a mini skillet (SEE "NOTES" BELOW) and bake for 10-12 minutes or until set.
While cake is cooling, slice strawberries and toss in sugar. Prepare the whipped cream by whipping the cream and sugar until soft or stiff peaks form.
To assemble, dust cooled cake with powdered sugar, add strawberries and top with whipped cream.
Notes
-You can use a 5" or 6" ramekin, skillet or pyrex bowl (as long as it's oven-safe).