Ingredients:

• 6 Tablespoons unsalted butter, room temperature
• 2/3 cup canola oil or vegetable oil 
• 1 1/3  cup granulated sugar 
• 2 2/3 cup all-purpose flour
• 1 Tablespoon baking powder
• 1 teaspoon salt
• 1 cup whole milk room temperature preferred
• 6 large egg whites room temperature
• 1 Tablespoon clear vanilla extract

Cannoli Filling

• 1/2 cup whipping cream
• 1 (15 oz) container whole milk ricotta cheese, strained of all liquid
• 1/2 cup powdered sugar
• 1/2 teaspoon vanilla
• 1 1/2 teaspoon orange zest
• 1/3 cup mini dark chocolate chips

Swiss Meringue Buttercream:

• 7 large egg whites 
• 2 cups sugar
• 1 1/2 cups (3 sticks)  unsalted butter, softened 
• 2 tsp vanilla extract
• 1/4 tsp salt 

• Preheat oven to 350F and prepare two 8-inch round cake pans by lining the bottoms with a round of parchment paper and generously greasing and flouring the sides. Be sure to shake out excess flour.
• In a stand mixer (or using an electric mixer), beat butter on medium-low speed until creamy.
• Add sugar and oil and beat until all ingredients are well-combined and creamy.
• Scrape down the sides and bottom of the bowl and then stir in your vanilla extract.
• In separate bowl, whisk together your flour, baking powder, and salt.
• Measure out your milk.
• With mixer on medium speed, gradually alternate between adding the flour mixture and the milk, starting and ending with the flour mixture. Stir until each one is almost completely combined before adding the next.
• Pause occasionally to scrape down sides and bottom of bowl.
• In separate bowl, combine your egg whites and, with a hand-mixer on high-speed, beat until stiff peaks form.
• Using a spatula, gently fold your egg whites into your batter. Take care to scrape the sides and bottom of the bowl so that ingredients are well-combined, and take care not to over-mix.
• Evenly divide cake batter into prepared pans.
• Bake on 350F for 35-40 minutes, or until a toothpick inserted in the center of each cake layer comes out clean or with few crumbs (should not be wet). For best results, rotate your cake pans halfway through baking to ensure even baking.
• Cakes will be a light golden brown when done baking.
• Remove cakes from oven and allow to cool for 15 minutes. Run a knife around the inside rim of each pan and invert each onto a cooling rack.
• Allow to cool completely before covering with buttercream frosting*.  I used a double batch of my recipe (linked above) to thoroughly cover and decorate this cake.  

Cannoli Filling:

In the bowl of a stand mixer fitted with a whisk attachment, whip the cream until stiff peaks form. Place the cream into a small bowl and set aside.

In the same mixing bowl, add the ricotta cheese, powdered sugar, vanilla, and cinnamon. Mix on medium speed until well combined, about 1 minute. Fold in the whipped cream and chocolate chips.

Chill the cream for at least 2 hours before filling the cannoli shells.

Swiss Meringue Buttercream

1. In a medium pot, add at least 1-inch of water and bring to simmer.
2. Thoroughly wash and dry the stainless steel mixing bowl from your stand mixer* (you don't want grease touching meringue). Add 7 egg whites and 2 cups sugar and whisk together. Place mixing bowl over pot of barely simmering water, creating a seal over the pot (bowl should be over the steam, not touching water). Whisk constantly until mixture reaches 160˚F (takes about 3 min). Sugar should be fully dissolved (you should not feel any sugar granules when rubbing mixture between finger tips). Mixture will feel hot to the touch.
3. Wipe water from bottom of mixing bowl and transfer bowl to stand mixer fitted with whisk attachment. Beat on medium-high speed until stiff glossy peaks form (about 15-20 min) and bottom of the bowl feels completely at room temp and not warm (important: warm meringue will melt the butter).
4. Once bowl is at room temp, switch to paddle attachment, reduce to medium speed and add butter 1 Tbsp at a time, adding it just as fast as it is absorbed by meringue. Once all butter is in, scrape down the bowl and continue beating until it reaches a thick whipped consistency (3 min on med-high speed). If it looks lumpy or liquidy at all, keep beating until smooth, thick and whipped.
5. Add 2 tsp vanilla extract and 1/4 tsp salt and mix on med-high until incorporated (about 1 min).