Pre-heat your oven to 100C Fan/225F/Gas Mark ¼, and line two or three baking trays (depending on size) with baking paper (once the meringue is ready you can use a little of it to stick the baking paper to the trays)
Finely grate the dark chocolate (I use a fine grater) and stir the cocoa powder into it
Whisk up the egg whites and cream of tartar in a food mixer until stiff peaks form, they will hold their shape but still be foamy
Keeping the mixer going, slowly add caster sugar a spoonful at a time. Wait about 15 seconds between each addition. Then add the vanilla extract. Once stiff peaks form, and you can rub the meringue between your fingers without feeling any sugar grains, turn the mixer off, the meringue will be thick, glossy and hold it's shape very well
Fold the chocolate and cocoa powder mix into the meringue gently
Put the meringue into a piping bag with a star nozzle and pipe out nest shapes onto the baking tray. Start by piping a circle, then pipe a ring on top of the circle. Or you can dollop the meringue onto the baking tray and use the back of a spoon to create a dent in the centre
Bake the meringue nests for 1 hour and 30 minutes. To avoid the meringue from cracking turn the oven off and do not open the door until the oven is fully cooled down. I usually leave them in there overnight
Whip up the double cream with the icing sugar and vanilla, then spoon it into the middle of each nest, add 3 Mini Eggs per nest (or more if you like!) and add some dark chocolate shavings (I use a vegetable peeler to make them)
Store in the fridge and eat within 2 days
Video
Notes
Make sure your eggs are at room temperature before you start baking.
If you don't have any cream of tartar, you can replace it with 2 tsp white vinegar, 2 tsp cider vinegar, or 2 tsp lemon juice.
You can use either fresh eggs, or to avoid having lots of egg yolks to use up you can now buy cartons of egg whites from brands like Two Chicks. I do find that you get the best and most consistent results with fresh eggs, but the cartons are great for avoiding egg yolk waste.
If you need recipes to use up leftover egg yolks, check out my Leftover Egg Yolks recipe collection.
Make sure your mixing bowl is completely grease free before making your meringue, as grease will stop the egg whites from foaming. You can wipe your bowl down with lemon juice or white vinegar before you start to ensure any traces of grease is removed.
When separating your eggs make sure not to get any egg yolk in the egg whites, as this will also stop it from foaming.
You can decorate the meringue nests with any Easter chocolate of your preference.
Although I provide cup measurements, I highly recommend weighing your ingredients out using digital kitchen scales. It is the most accurate way to measure ingredients and will ensure the best results. Digital scales are very low cost and can be purchased for around £12 ($16.50).
For teaspoon (tsp) and tablespoon (tbsp) measurements, please use measuring spoons and not the type of spoons you eat with. Again this will ensure accuracy and provide the best results.