Preheat the oven to 375° Fahrenheit. Prep a cookie sheet or jelly roll pan: grease with butter or spray, line with parchment paper, then grease the paper. Using an electric mixer with clean beaters, beat egg whites and cream of tartar until soft peaks form. Add 1/3 of the sugar and continue beating until stiff peaks form, set aside. In the egg yolk bowl, add the other 1/3 cup of sugar and beat until thicker and lighter, about a minute. Add the flours, starch, salt, powdered strawberries, jam, and orange blossom water and beat. Fold in the egg whites 1/3 at a time until smooth and combined. Pour into prepared pan and spread evenly with a spatula. Bake for 14-16 minutes until spongy to the touch, then remove and let cool slightly.

When cake has slightly cooled, lift parchment paper and cake out and place on a dampened kitchen towel. Sprinkle with powdered sugar and carefully roll entire cake using parchment paper and towel. Let sit, rolled with the towel inside, until completely cooled.

While cake is rolled and cooling, make the filling! Using the electric mixer, beat the heavy cream and cream of tartar until soft peaks form. Add the sugar, orange blossom water, and mint and continue to beat until stiff peaks form. Reserver 1 cup whipped cream in a piping bag for the topping. When cake is cooled, carefully unroll. Use a spatula to spread the remaining whipped cream evenly across the entire cake. Re-roll the cake and wrap in the parchment paper - chill in fridge or freezer for 30 minutes to an hour.

Remove cake from freezer or fridge and unwrap. Plate the cake and pipe the reserved whipped cream onto the top of the cake. Top whipped cream with mint sprigs and strawberries (optional). Cake can keep in the fridge or freezer.