Grease two 5-inch pans and three 7-inch pans, line with parchment rounds and place on a cookie sheet. Set aside.
Sift all the dry ingredients into a large bowl and make a well in the centre.
In a separate bowl, lightly whisk together all the wet ingredients, except coffee.
Add the wet mixture to the dry ingredients and use a whisk to stir the batter. It will be thick.
Add the hot coffee and continue to stir with the whisk until fully combined.
Divide the batter evenly into prepared cake pans. (I place each pan on a scale for even distribution - anal, I know...)
Bake for 25-30 minutes on the cookie sheet on the middle rack of the oven. Rotate cookie sheet halfway through baking. The smaller cakes will bake faster than the larger ones, so keep an eye on them.
Remove from oven and allow to cool in pan for 10 minutes before turning them out onto a cooling rack.
Once completely cooled, level and torte cakes.
Make the peanut butter buttercream:
Using a clean towel and some lemon juice or vinegar, clean your mixing bowl, whisk attachment and utensils to remove any traces of grease.
Fill a heavy duty pot about a quarter of the way with water and place on the stove over medium heat to simmer.
Add egg whites, sugar and a pinch of salt to the bowl of a stand mixer and place over the pot of simmering water, ensuring the bottom of the bowl is not in contact with the water in the pot.
Whisk the sugar, egg white, salt mixture constantly, but gently, until temperature reaches 160°F.
Once at the correct temperature, remove from heat and dry the underside of the bowl with a towel before placing it on the stand mixer.
With the whisk attachment, begin to whip the meringue until it is thick, glossy, and the bottom of the bowl is no longer warm to the touch. Do not begin adding butter while the bowl is still warm.
Switch from your whisk to paddle attachment and with mixer on low speed, add butter cubes, one at a time, until incorporated. Continue to mix until it reaches a silky smooth texture.
Add vanilla and peanut butter, continuing to beat on low speed until well combined and silky smooth.
Make the gianduja buttercream:
Roughly chop the gianduja andadd to a small bowl. Please the small bowl over a pot with simmering water to melt. Set aside to cool.
Using a clean towel and some lemon juice or vinegar, clean your mixing bowl, whisk attachment and utensils to remove any traces of grease.
Fill a heavy duty pot about a quarter of the way with water and place on the stove over medium heat to simmer.
Add egg whites, sugar and a pinch of salt to the bowl of a stand mixer and place over the pot of simmering water, ensuring the bottom of the bowl is not in contact with the water in the pot.
Whisk the sugar, egg white, salt mixture constantly, but gently, until temperature reaches 160°F.
Once at the correct temperature, remove from heat and dry the underside of the bowl with a towel before placing it on the stand mixer.
With the whisk attachment, begin to whip the meringue until it is thick, glossy, and the bottom of the bowl is no longer warm to the touch. Do not begin adding butter while the bowl is still warm.
Switch from your whisk to paddle attachment and with mixer on low speed, add butter cubes, one at a time, until incorporated. Continue to mix until it reaches a silky smooth texture.
Add the gianduja slowly pouring in a constant stram, continuing to beat on low speed until well combined and silky smooth.