Heat your oven to 375ºF and, using 1 tablespoon of the butter, grease a standard pie plate or small casserole dish.
In a large bowl, whisk the eggs with the sugar, milk, vanilla extract, almond extract, lemon zest, and the remaining 3 tablespoons of melted butter. Add in the flour, almond flour, and salt and whisk to combine.
Pour the batter into the prepared dish and scatter over the raspberries and sliced almonds.
Bake the clafoutis for 35 minutes or until the edges are puffed and the middle is almost set.
Cool slightly or all the way to room temperature and serve dusted with icing sugar.
