To make the cake:

1. Preheat the oven to 350 degrees Farhenheit. Lightly grease 2-6” round cake pans and cut out rounds of parchment paper to fit inside of the bottoms. 
2. In a large bowl, cream together the butter and sugar on medium speed, scraping the bowl occasionally, until light and fluffy, about 4 minutes. With the mixer on low, add the yolks one at a time, followed by the extract. Scrape the sides of the bowl and stir in any unincorporated bits. In a small, separate bowl, stir together the cake flour baking powder, and salt. Add half of the mixture to the butter, stirring on low until nearly integrated. Add the milk and stir. Scrape the bowl and add in the remaining dry ingredients. Fold the mixture until smooth.
3. Divide the batter between the two pans and bake in the preheated oven for about 22-23 minutes, or until a toothpick inserted comes out clean. Allow to cool completely. 

To make the frosting:

1. Combine all of the ingredients in a medium-sized saucepan over low heat. Stirring consistently, melt the ingredients until the mixture is nearly smooth. Remove from heat and allow the mixture to melt completely. Pour the mixture into a bowl and place in the fridge. Allow to cool, stirring ever 15 minutes or so, until the mixture comes to a thickened, fudgy consistency. Then frost the cake. Level the cakes using a serrated knife and use and offset spatula to smooth the frosting on top of the first layer. Place the second cake on top and finish frosting as desired.