Boston Cream Pie from Scratch

Yellow Cake

1. Preheat oven to 350° and grease the inside of an 8" round cake pan.
2. In a large bowl or stand mixer, combine softened butter and sugar. Cream together, using hand mixer or stand mixer, at medium speed for 2-3 minutes until combined and slightly lighter in color.
3. Reduce speed on the mixer to low and slowly add in vegetable oil, milk, vanilla and eggs.
4. In a separate bowl, combine flour, baking powder and salt and whisk to combine. Add into the the mixer with the wet ingredients and mix on low until everything is just combined.
5. Pour cake batter into prepared cake pan and bake for 20-25 minutes until the sides start to pull away from the outside of the pan and a toothpick comes up clean when inserted into the middle of the cake. Remove cake from the oven and allow to cool while you make your pastry cream.

Pastry Cream

1. In a small bowl combine egg yolks, cornstarch, salt, and only ¼ cup of the sugar. Whisk to combine.
2. In a medium saucepan, combine milk and remaining ¼ cup of sugar. Heat over medium heat until mixture comes to a simmer. 
3. Spoon a small amount of the hot milk mixture into the egg mixture and whisk to combine. Once the egg mixture is mixed and warm to the touch, add back into the milk mixture and whisk to combine. This will slowly warm the egg mixture so it will not scramble.
4. Continue cooking the mixture over medium heat while whisking vigorously until mixture comes to a boil and begins to thicken. Cook for an additional 2-3 minutes to make sure the cornstarch has been cooked out.
5. Remove the pastry cream from the heat and whisk in the butter until. Continue to milk until all of the butter pieces have melted and are combined well with the cream. 
6. Place the cream in a bowl and cover with plastic wrap so that the wrap is directly on the pastry cream. This will make sure that a skin doesn't form on the top of the cream.
7. Place the pastry cream in the refrigerator and cool completely before using. Remove the cake from the pan it was baked in and allow to cool on a wire rack completely.

Cake Assembly

1. Once the cake and pastry cream have cooled completely, use a serrated knife to cut through the middle of the cake to create two equal layers.
2. Add the bottom layer to serving plate or platter and top with pastry cream, leaving ½" of space around the edges.
3. Carefully add the top layer of the cake to the pastry cream being careful as to not squish the pastry cream out of the sides. Place cake in the fridge while you make the chocolate ganache.

Chocolate Ganache

1. Place chocolate chips in a heatproof bowl and set aside.
2. Add heavy cream to a saucepan and heat over medium heat until the cream starts to create small bubbles on the surface.
3. Remove cream from the heat and pour over the chocolate chips. Allow to sit for 1 minute.
4. Whisk together the chocolate and cream until all of the chocolate is melted and incorporated together with the cream.
5. Remove cake from the fridge. Pour chocolate ganache on top of the cake, starting in the middle until it starts to drip down the sides of the cake. Use a spoon to push the ganache over the sides if needed.
6. Chill cake for 1-2 hours to set the ganache completely.