Hydrate <quantity>6<unit>g</unit></quantity> of unflavored powdered gelatin in <quantity>30<unit>ml</unit></quantity> of water

Fill ⅓ of a small pan with water and bring it to a simmer. Place the hydrated gelatin bowl inside of it and warm it up until the gelatin is dissolved

Add <quantity>300<unit>g</unit></quantity> of heavy cream to a saucepan and warm it up over low heat

Pour some of the warm cream over a bowl with <quantity>60<unit>g</unit></quantity> of egg yolk and mix to combine

Transfer the heavy cream and egg yolk mixture back to the saucepan and mix. Cook over low heat until it reaches <temperature>80<unit>°C</unit></temperature>

Place <quantity>490<unit>g</unit></quantity> of white chocolate chips in a large bowl and pour the warm heavy cream mixture over it

Add the hydrated gelatin and mix . Let the bowl sit for 3m until the chocolate chips are melted

Add <quantity>450<unit>g</unit></quantity> of heavy cream to a bowl. Whisk until you obtain stiff peaks

Blend with a hand mixer until all the chocolate has melted and the mixture is homogeneous

Gradually add the whipped cream into the chocolate mixture, gently folding to combine with each addition. The white chocolate mousse batter is ready

Add <quantity>1<unit>cup</unit></quantity> of milk to a pan and warm it up over medium heat. Remove from the heat before it starts to boil

Add a thin layer of the White Chocolate Mousse Batter into a container

Break <quantity>500<unit>g</unit></quantity> of large chocolate chip cookies in half. Dip them into the warm milk and place on top of the mousse to create a layer of cookies

Cover the cookies with more chocolate mousse, and repeat the process of creating layers until the last layer of mousse. Leave <quantity>1<unit>in</unit></quantity> for later

Take it to the refrigerator for at least 4h to set

Melt <quantity>85<unit>g</unit></quantity> of butter with <quantity>250<unit>g</unit></quantity> of heavy cream in a small saucepan over low heat

Add a pinch of salt and stir to dissolve

Add <quantity>100<unit>g</unit></quantity> of milk chocolate chips and <quantity>180<unit>g</unit></quantity> of dark chocolate chips to a bowl. Pour the hot cream and butter mixture over

Use a hand blender to combine the melted chocolate with the cream. The chocolate ganache is ready

Pour the Chocolate Ganache over the mousse and spread it to create an even layer

Cut a piece of parchment paper into a triangle and roll it to form a cone. Fold the edges inwards

Fill the parchment paper cone with <quantity>⅓<unit>cup</unit></quantity> of melted white chocolate. Twist the top to close it and cut off the tip

Use the white chocolate to draw a pattern on the surface. You can use a toothpick to create different designs

Place it in the refrigerator for 4h to set. The cookie trifle is ready

Enjoy! This is perfect for the holidays!