I love meringues in slices – marshmallow without the gelatine. This is from High Tea (Viking, 2014), it contains 200 recipes! They used macadamia nuts but I had some roasted peanuts I wanted to use up. I found the slice a bit dry and needed some cream to go with. I think next time I would blind bake the base first and then add a caramel sauce with the nuts before topping with meringue. Or if you don't feel like nuts you can just add jam and coconut in the meringue and it would become a Louise slice.
100g softened butter
½ c caster sugar
2 eggs, separated
½ tsp vanilla extract
1 ½ c flour
pinch salt
1 tsp baking powder
1 c macadamia nuts, chopped
1/4 c soft brown sugar

Preheat oven to 180C. Lightly grease and line a 20 cm x 30 cm slice tin.
Cream butter and sugar until light and fluffy. Slowly whisk in one egg and the yolk of the other egg. Separate the other egg white into another bowl. Add the vanilla and beat well.
Mix in sifted flour, baking powder and salt. Press into the tin and sprinkle with the nuts.
Beat remaining egg white until stiff peaks form, then fold in sifted brown sugar. Spread meringue over the top of the slice and bake for 20-25 min. Check halfway through the cooking time. If the meringue is getting too dark put some foil on top.
When cool, cut into squares.