Flavored Italian buttercreams
Equipment:
Candy thermometer
Stand mixer fitted with whisk attachment - note, you can do this with a hand mixer, but you will definitely need a helper for safety when pouring the boiling hot sugar syrup.
Espresso frosting, makes a little over 3 cups of frosting
1-1/3 cups sugar, divided
4 oz water
4 large egg whites at room temperature 30 minutes
1 Tbsp plus 2 teaspoons instant-espresso powder
3/4 Tbsp pure vanilla extract
3/8 tsp cream of tartar
1/8 tsp salt, rounded
4 sticks (3/4 pounds) unsalted butter, cut into tablespoon pieces and softened to room temperature
Brown gel or paste food coloring for a darker bark if desired
Vanilla and Chocolate filling, makes a little over 3 cups frosting in total, I divided.
1-1/3 cups sugar, divided
4 oz water
4 large egg whites at room temperature 30 minutes
3/4 Tbsp pure vanilla extract
3/8 tsp cream of tartar
1/8 tsp salt, rounded
4 sticks (3/4 pounds) unsalted butter, cut into tablespoon pieces and softened to room temperature
3 ounces fine-quality 60%-cacao bittersweet chocolate, melted and cooled to just above room temperature (for 2 cups of chocolate and a little over 1 cup of vanilla buttercream. Add another 1-1/2 ounces of chocolate if you want all chocolate.)
Bring 7/8 cups sugar and water to a boil in a large heavy saucepan fitted with candy thermometer (make sure bottom of thermometer is not touching bottom of pan) over medium heat, stirring until sugar has dissolved. If there are any sugar crystals on side of pan, brush down gently with a pastry brush dipped in cold water. Then, bring to a boil and let cook, without stirring, until mixture registers 235 to 242 Fahrenheit, 15 to 20 minutes.
While syrup is boiling, beat whites with espresso powder, vanilla, cream of tartar, and salt in mixer at medium speed until they just hold soft peaks. Add remaining sugar, about 1 tablespoon at a time and beat until whites just hold stiff peaks. Optional: Add in desired amount of food coloring a couple drops at a time while you are beating in the sugar.
When syrup reaches temperature, immediately start to pour syrup in a slow stream down side of bowl into whites (avoid beaters) while beating at high speed. Beat until the mixture is completely cool, 25 to 30 minutes. It is important that meringue be completely cool and at room temperature so that butter does not melt.
Then, with mixer at medium speed, add butter 1 tablespoon at a time, beating well after each addition until buttercream is smooth. (Mixture may look curdled before all butter is added but will come together at end.)
Transfer 2 cups buttercream to a small bowl and stir in chocolate.
If buttercreams are too soft to spread, chill, stirring occasionally.