A trick we have done over the years in the Canadian Living Test Kitchen is to lighten up whipping cream by replacing almost half with drained yogurt. The results are a tangy, creamy and rich tasting topping. This would work very well as a filling for a dacquoise. You can add flavouring to the whipped cream if you like (e.g liqueur, coffee, orange or lemon rind, etc.). You could also add fresh fruit in the layers.

Depending on the amounts in your recipe, this is just a base to start with: Spoon 2 cups (500 mL) plain Balkan yogurt into cheesecloth-lined sieve set over bowl. Refrigerate for 1 hour, discarding whey in bowl. Whip 1 to 1-1/2 cups (250 to 375 mL) whipping cream with about 2 tbsp (25 mL) icing sugar (more or less depending on your taste) and 1 tsp (5 mL) vanilla. Fold drained yogurt into whipped cream.

Dacquoise recipes:
Mocha Cream Dacquoise
Orange Pecan Dacquoise
Lemon Dacquoise
Desserts Plus's Coffee Dacquoise Torte