Hull the strawberries and cut them in half. Place them in a bowl and add the lemon juice and 20g of sugar. Mix together and set aside.
Place the well chilled cream into a mixing bowl and whip using an electric whisk. When it begins to thicken, add 20g of sugar, 1 pinch of powdered vanilla and continue to whisk until firm. Cut the muffins in half, spread each side with strawberry jam. Distribute half of the strawberries and close the muffins.
Toast them in the appliance for 5 minutes. Decorate with the chantilly cream and remaining strawberries to serve.