Chocolate Hazelnut Tart

5 from 6 votes

Prep Time1 30

Cook Time20

cooling4

Total Time5 50

Course: Afternoon Kaffee, Dessert

Cuisine: American, German

Keyword: Chocolate, hazelnut, tart

Servings:

Calories: 394kcal

95 grams unsalted butter
80 grams granulated sugar
1/2 teaspoon fine sea salt
1 teaspoon vanilla extract
30 grams cocoa powder natural or dutch processed, plus a little extra reserved for dusting
125 grams all purpose flour

280 grams hazelnuts preferably toasted and peeled, 220 grams for the nut butter, 60 grams for sprinkling
250 grams condensed milk
1 teaspoon vanilla extract
2 pinches flaky sea salt
225 grams heavy cream cold

Preheat the oven to 350º F and place a rack in the center of the oven.
Cut the butter into 1" cubes and add to a heat and microwave safe bowl. Heat briefly in 15 second intervals until the butter has just started to melt but isn't fully melted.
Add the sugar, vanilla, and salt into the bowl with the butter and whisk to combine. Pour in the cocoa powder and whisk once more.
Pour in the flour and use a fork to cut the butter into the flour. Mix until just combined.
Place the tart pan on a baking sheet.
Pour the crust (adjust as needed for the size of your pan) into the tart pan. Press the crust into the sides of the pan and across the bottom with your fingers. Use your thumb or your pointer finger to really press it into the bottom corner so that you don't get a super thick pastry corner.
The crust should be just thick enough that you can't see the pan poking through.
Place the tart in the fridge to chill for 10 minutes.
Bake in the preheated oven for 20-25 minutes until it looks dried but not darkened.
Once baked, remove the pan from the oven and set aside to cool.

If needed, toast the hazelnuts in a pan over medium low heat in a single layer until the oils start to release and the hazelnuts start to get fragrant. Pour the hazelnuts into a jar, cover with a lid and shake to remove the skins.
Chill the hazelnuts in your freezer until cold.
Pour the 220 grams of cold, peeled, toasted hazelnuts into a blender or food processor. The smaller the blender the better they will blend.
Blend the hazelnuts into a smooth butter, scrape down the sides as needed.
Pour the hazelnut butter into a bowl and then add in the condensed milk, and vanilla, stir to combine. If the mixture is quite runny, place it in the fridge for 10-15 minutes to help it firm up. You're looking for a thick caramel kind of texture.
While the mixture chills, chop the remaining hazelnuts and set aside.
Pour about 325 grams of the chilled mixture into the cooled tart crust. Sprinkle with the chopped hazelnuts and a couple pinches of flaky sea salt. Place the tart in the fridge while you prep the chocolate filling and hazelnut whipped cream.
In a separate bowl, whip the cold heavy cream into stiff peaks.
Spoon about 50 grams of the whipped cream into the remaining hazelnut mixture and stir to combine. This softens the hazelnut mixture making it easier to fold the cream in.
Add in half of the remaining whipped cream and use a flat rubber spatula to fold it in, trying not to deflate the cream. Fold in the remaining half of the cream and place it in the fridge until you're ready to assemble.

In a medium mixing bowl, add in the cold mascarpone, 75 grams of heavy cream, sugar, salt, vanilla and cocoa powder.
Use the paddle attachment on medium low speed to cream the mixture together until smooth.
Turn off the mixer and pour in the remaining cold heavy cream.
Mix on medium speed until it begins to thicken and lines form. It thickens quickly so stop before it is stiff. Do not over whip it, it's better to under whip rather than over whip. If you over whip it, pour in a little extra heavy cream and use a rubber spatula to fold it in.
Set aside until ready to assemble.

Continue assembling the tart.
Spoon the chocolate mascarpone filling over the hazelnut layer and carefully spread it to the edges of the tart. Try not to disturb the hazelnut layer underneath.
Pour the hazelnut whipped cream on top and smooth out the surface with a spoon or an offset spatula if you want it really smooth.
Place it in the fridge to chill for 1 hour, then cover with a sheet of plastic to keep it from drying out too much. Leave to chill for another 3 hours or up to overnight.
Once chilled, remove the tart from the fridge. Remove it from the form by pressing the bottom of the pan up and out of the rim. Then use a metal spatula or the tip of a sharp knife to carefully pry the tart away from the pan.
Place the tart on the dish or stand you plan to serve it from.
Dust the top with cocoa powder through a sieve.
Use a long sharp knife to cut the tart, clean the blade in between each slice to keep the cuts neat.
Store any extra tart in the fridge or freezer to keep it firm.

Tips for making Chocolate Hazelnut Tart

Be careful when melting the butter for the crust if you are doing it in the microwave. Butter can easily explode so I recommend melting it in 10-15 second bursts and stirring the butter in between until melted.
If you're struggling to get a smooth edge at the top edge of the tart, use a knife to slice, level with the top of the pan, the top edge of the crust. Use any excess to even out the bottom of the tart.
Trader Joe's sells already toasted hazelnuts that are also mostly peeled which work perfectly for this but there are also steps in the recipe which tell you how to toast and peel the hazelnuts.
I find it easiest to make the hazelnut butter when the hazelnuts are cold because it helps keep the oil from separating. Be careful not to let the blender overheat, take breaks in between if you need to but you should be ok. For the best texture for the fillings, blend them until they are as smooth as possible.
Do not to over whip the mascarpone frosting. It can easily split if you do, so it’s better to stop when it is still soft and if needed, whip a little more by hand just before assembling.
If the tart is too soft when slicing, place it in the freezer for 30 minutes to firm it up.
I like to store the tart in the freezer because it is quite soft (and lowkey it tastes delicious frozen too) but it also defrosts quickly and well in the fridge!