Place the rhodoid in the molds, then place them on a baking sheet covered with parchment paper (or a silicone mat)
Speculoos dough (the day before)
Put the speculoos in the bowl of a blender. Blend to a powder.
Add the melted butter. Mix again to obtain a homogeneous mixture.
Pour the mixture into the bottom of the molds, pressing well to combine.
Set aside in the fridge.
Mascarpone whipped cream (the day before)
In a large bowl (preferably cold, you can put it in the freezer for about 30 minutes. This will help the whipped cream set faster), pour in the cream, mascarpone and confectioners' sugar. Whip until you get a firm whipped cream.
Spread the cream on the speculoos paste (keep some for decoration, if you wish). Then place in the freezer.
Strawberry jam (the day before)
Mix half the sugar with the pectin.
Place strawberries, coarsely chopped, in a saucepan with remaining sugar and lemon juice. Bring to a boil.
Add the sugar/pectin mixture, stirring well. Simmer over medium heat for about 10 minutes (there will still be small pieces of fruit, this is intentional).
Let cool, then spread the jam over the creams (which were in the freezer). Return the entremets to the freezer and leave them overnight.
On the day
Remove the entremets from the freezer. Unmold them while they are still frozen. Remove the rhodoid.
Decorate with fresh strawberries and remaining whipped cream (optional).
Let the entremets thaw in the fridge for at least 2 hours.