I used these cubed chocolates. It will be too sweet if you use milk chocolate. Use bitter chocolate if you like it slightly sweet!

Use one pack (44 pieces) of cubed chocolate. If you are using chocolate bars, use about 4 bars.

These biscuits are sold in the 100 yen shop. It weighs 120 g.

Make a 1 cm cut into the biscuit bag, to remove the air. Tape it back together and crush the biscuits finely with a rolling pin.

Microwave the butter for 20-30 seconds to melt it. (adjust the time accordingly.)

Open up the biscuit bag, and pour in the melted butter. Mix together very well.

Line the sides of a springform pan with parchment paper, and press in the mixture from Step 6. (you do not have to line parchment paper on the bottom.)

Gently flatten the surface by pushing hard with a spoon or spatula to harden and meld the crumbs together.

Chop the chocolate roughly to make it easier to melt, and put it in a bowl. Put heavy cream in a pan and simmer.

When the heavy cream has warmed up, immediately pour it in the chocolate. (The pieces of chocolate melted even though I did not chop them.)

Immerse the chocolate so that you do not see it, and wait for about 30 seconds to 1 minutes without stirring. (This is to heat up the core of the chocolate before mixing.)

Try not create bubbles and stir gently to melt the chocolate. (It will be difficult to stir at the beginning, but continue stirring. Place the bowl on a double boiler if the chocolate has difficulty melting.)

It will become shiny when everything is mixed evenly, so continue mixing until it becomes shiny. (Be careful not to create bubbles!) You can also add a little bit of your favorite liqueur if you like !

Pour Step 13 into the cake pan from Step 8 and chill in the refrigerator to firm up. (Let it chill until the evening if you made it in the morning, and let it chill overnight if you made it in the evening.)

Take it out of the mold when the chocolate truffles has hardened. You can also say that it is already ready at this point! Or you can sprinkle cocoa powder on the surface. In that case, don't keep some of the chocolate mixture for decoration in Step 14 and pour all of the mixture into the cake pan to let it all harden.

If you kept some of the chocolate mixture from Step 14, keep it in the refrigerator. Mix it with a rubber spatula, then it will be ready to put in the pastry bag.

After taking removing the sides of the pan and the parchment paper, slightly mark the cake where you are going to cut it before eating using a knife. (This process is to make it easier to know where to squeeze out the chocolate mixture in the next step.)

This time, I used a round tip which is about 5 mm to squeeze out the chocolate mixture from Step 17, and made a heart shape. (Save any of the chocolate mixture remaining after decorating.)

Sprinkle cocoa powder using a tea strainer.

Slightly warm up the chocolate mixture remaining from Step 19 to make it creamy. (Be careful not to burn it. You can heat it up quickly over direct heat. You can also warm it up with a double boiler).

Pour the mixture from Step 21 into the middle of the heart shape using a spoon.

The thickness of the tart when it is ready is pretty thin, so if you want to make it thicker, use more chocolate and heavy cream, or use a smaller cake pan. You can even mould this tart in a milk carton.

I recommend the baked tart. The baked type tart is more difficult to melt than the chocolate truffle tart, so I recommend it if you are going to take it somewhere on a hot day.