Wipe down bowl of stand mixer, whisk attachment and paddle attachment with lemon juice. This will remove any grease or residue on your equipment that might prevent the meringue from properly whipping.
Honey Buttercream
Weigh out the egg whites, honey, and granulated sugar into the bowl for the stand mixer. Whisk together by hand to evenly distribute into a liquid mixture.
Place a medium saucepan filled about 1-inch deep with water on medium heat and bring to a simmer.
Set the metal mixing bowl on top of the pot to create a double broiler. Whisk constantly and gently until the mixture reaches 160℉ (72℃) on a probe thermometer.
Remove the bowl from the pot, wipe of the bottom with a towel and place in the stand mixer. With the whisk attachment, beat on medium speed until frothy, then increase to high. Mix until glossy stiff peaks are formed.
The bowl should now be about room temperature, maybe just slightly warm at the center of the bottom. If the bowl is still hot, let it cool some before adding in the butter.
Once the mixture reaches stiff peaks, switch to medium speed and add in the softened butter cubes a couple at a time until fully mixed in. I mix the butter in with the whisk attachment, but you can swap over to the paddle attachment for this as well.
450 grams unsalted standard butter or European style butter
When half of the butter has been added in, give the sides and bottom of the bowl a scrape with a rubber spatula. Continue mixing in the rest of the butter. It might be curdled or chunky, but that’s ok. Keep on mixing and be patient. It will take a moment to fully emulsify and magically turn into frosting
Now that it looks smooth, add in the vanilla and extra honey for a few spins. Taste and adjust. If it's too sweet, toss in a pinch of fine sea salt.
1 teaspoon vanilla bean paste or pure vanilla extract, 42 grams honey
For an extra super silky, shiny, smooth buttercream turn the speed down to low. Keep mixing with the paddle attachment until you like the texture. This could be 8-15 minutes.