Easy

unit

Preheat oven to 210°C 
Melt the diced butter in a bowl, then add 3 tablespoons of speculoos dough and mix until smooth.

In a bowl, add the eggs, flour and sugar and whisk until a dough forms, then add the butter/speculoos mixture and mix again.

Pour into buttered muffin tins or verrines (like me) add 1 heaping tablespoon of speculoos paste to the middle of each fondant. 
Bake for 8 to 10min.