Step 1

Preheat oven to 325 degrees F.

Step 2

Line the bottom of a 9 inch spring form pan with parchment paper but do NOT grease the sides. Greasing the sides will not allow the cake to rise well and since the cake is cooled in the pan, the ungreased sides provide support for the cake as it cools so that it will not shrink.

Step 3

In the bowl of an electric mixer, using a whisk attachment, combine the sugar, eggs and vanilla extract and beat on medium high speed for about 10 minutes until the mixture is foamy and pale in color.

Step 4

Reduce the speed of the mixer to medium low and with the mixer running, begin to continuously sprinkle in rounded tablespoons of the flour. Stop the mixer as soon as the flour is fully incorporated.

Step 5

Remove 1 cup of the sponge cake batter and mix it with the melted butter.

Step 6

Immediately add this mixture back into the main batter, folding it in very gently with a rubber spatula. Make sure the butter mixture is fully mixed in but be careful not to over mix the batter when folding as this can cause the batter to deflate.

Step 7

Pour the batter into the prepared spring form pan and bake for approximately 25-30 minutes or until the top springs back fully when pressed lightly. Watch this cake closely as it will over bake easily if left for 5 minutes too long. Start checking it at the 20 minute mark just to be sure.

Step 8

Cool the cake completely IN THE PAN for at least an hour or two.

Step 9

When the cake is completely cool you can line the inside of the pan with strawberry slices if you like.

Step 10

Mix the gelatin in the 1/4 cup of water and set aside.

Step 11

Start by adding the strawberries & sugar to a medium sized saucepan.

Step 12

Bring to a gentle boil and simmer for 5 minutes.

Step 13

Remove the pan from the heat and mash the berries a little with a potato masher or fork.

Step 14

Stir in the gelatin and water mixture until the gelatin is completely dissolved.

Step 15

Add the mini marshmallows and stir constantly until they are completely melted. This will take about 5 minutes.

Step 16

Transfer the mixture to a bowl to cool down to almost room temperature.

Step 17

Beat the whipping cream to soft peaks and fold it through the cooled strawberry marshmallow mixture.

Step 18

Pour the mixture into the prepared springform pan with the cake in the bottom.

Step 19

Chill for several hours or overnight to let the mousse set properly.

Step 20

Slowly run a sharp knife around the side edge of the pan, being careful to keep the knife firmly against the side of the pan, so as not to disturb the strawberry slices around the perimeter.

Step 21

Simply whip all of the ingredients together until firm peaks form.

Step 22

Use a piping bag with a large star tip to create a border of cream around the cake. For a simpler border, you can just use a ziplock bag with the corner snipped off to create a 1/2 inch opening, and use that as a piping bag.

Step 23

Add extra slices of strawberries to garnish if you like.