Instructions

For the Peanut Butter Cake

1. Preheat oven to 35o degrees F. Spray three 8-inch or four 6-inch pans with nonstick spray, line the bottoms with parchment paper and spray again. Set aside.  
2. Sift together the flour, baking powder, salt, and cinnamon. Set aside.
3. In the bowl of an electric mixer fitted with a paddle attachment, mix together the butter and peanut butter until creamy. Add in the sugar and mix on medium for about 3 minutes. 
4. Decrease the speed to low and add in the vanilla and eggs, one at a time. Stop the mixer and scrape down the sides and bottom of the bowl.
5. With the mixer on low, add in half of the flour mixture, then stream in the buttermilk and mix until incorporated. Add in the remaining flour and mix until combined. 
6. Evenly divide the batter between the cake pans and bake for about 23 to 25 minutes or until a toothpick inserted in the center of the cakes comes out clean. Cool on a wire rack for 10-15 minutes before removing the cakes from their pans.

For the Peanut Butter Frosting

1. In the bowl of electric mixer fitted with the paddle attachment, combine the butter and peanut butter. Beat on medium-high speed until smooth, about 45 seconds.
2. Add the powdered  sugar to the bowl and mix in, slowly at first until incorporated, then increasing the mixer speed to high. Blend in the vanilla extract, salt and heavy whipping cream, and continue to whip on high speed until very fluffy, about 4-5 minutes, scraping down the sides of the bowl as needed. 
3. To remove air bubbles from the frosting, use a wooden spoon to stir and push out the air bubbles.

Assembly

1. Place your first layer on the cake board. Spread about 1/2 cup of peanut butter frosting on the cake and then pipe a border of the peanut butter frosting around the edge to create a wall for the jam. Fill the center with about 1/2 cup strawberry jam and carefully spread it around. Don't add too much jam or the cake will be unstable as you continue to stack and frost.
2. Place the second layer of cake on top of the first layer and repeat step one.
3. Place the third layer of cake, bottom side up, on the second layer and spread a thin layer of frosting around the entire cake to create a crumb coat. Freeze the cake for 10 to 15 to set the crumb coat.
4. After the crumb coat is set, continue to frost the cake with the remaining frosting. 
5. If you use a cake board on top of the cake like I did in my video above, you'll want to freeze the cake again for another 20 to 30 minutes after you've frosted the sides and before you take the cake board off the top. This will ensure you get sharp edges when you cut it off with a knife. You'll then add frosting to the top of the cake after you've removed the cake board.