Looking for a lemon mouse type filling for a 3d cake.

bettercreme or pastry pride, one box instant lemon pudding and a little bit of lemon extract would make a great moussey-type filling. if you can't get bettercreme or pastry pride, you can use cook whip.

good luck!

The filling for this lemon chiffon pie could be used:

http://www.epicurious.com/recipes/recipe_views/views/235364

I make this for a fluffy lemon filling and it is very good..

Limoncello Lemon Cream

3 to 4 lemons
6 large egg yolks
1 cup sugar
6 tablespoons cold butter, diced
1/4 cup limoncello liqueur

1 cup heavy cream
1/4 cup sugar

Step one: make lemon curd

Finely grate enough lemon zest to equal 2 teaspoons. Squeeze enough juice to equal 1/2 cup. Strain juice through a fine, wire-meshed strainer. Set aside.

Fill a medium saucepan with enough water to come 1 1/2 inches up the sides of the pan. Bring to a simmer over medium-high heat. In a heat-resistant bowl, whisk together the egg yolks and sugar until pale and slightly thickened. Add the reserved zest and juice and whisk to combine.

Set the bowl with the egg mixture over the simmering water and whisk constantly until mixture thickens, 10 to 12 minutes. The mixture will turn a light yellow color and coat the back of a spoon. Remove the bowl from the heat and whisk the diced butter into the curd, 1 tablespoon at a time, allowing each piece to incorporate before adding the next. Stir in the limoncello. Strain the curd through a wire-meshed strainer and place in a clean, non-reactive container. Cover with plastic wrap, pressing the plastic wrap onto the surface of the lemon curd to keep a skin from forming. Chill completely.

Step 2: make whipped cream

When your curd has firmed up whip the heavy cream and 1/4 c sugar to stiff peaks and fold into the curd and then put in the fridge for an hour or so.

It's not quick.. but it is pretty easy and the flavor is wonderfully lemony.