White Chocolate Buttercream Frosting

1 (4-oz) white chocolate bar, broken into pieces
1/3 cup heavy cream
1 cup butter, softened
1 (2-lb) package powdered sugar
1/4 cup heavy cream
1/8 tsp. kosher salt
2 tsp. vanilla extract

1. Microwave chocolate and 1/3 cup heavy cream at Medium (50% power) 1 to 1.5 minutes or until melted and smooth, stirring at 30 second intervals. Let cool to room temperature (30 minutes).
*Since i do not know how to program the microwave for 50% power, i microwaved mine at full power at 15 second intervals. Total 45 seconds. 
2. Beat butter at medium speed until creamy; gradually add powdered sugar and 1/4 cup heavy cream, 1 tbsp. at a time, beating at low speed until blended after each addition.
*I thought i was seeing it wrong when it said 2 pounds of sugar but it was correct. That way the frosting becoming a bit hard and does not leak off the cake. Also, i did not do it by 1 tbsp. at a time, i dumped a decent batch of sugar each time. 
3. Beat in salt and chocolate mixture until light and fluffy. Stir in vanilla.
*This comes out tasting as if made in some fancy bakery. The only thing is i would cut everything in half because i had plenty of frosting left over. 
*The frosting comes out white so i covered the cake with it but i wanted the decorations on top to be a different color so they would not blend in. You can either add food coloring to the remaining frosting or what i did was add raspberry jelly and mix it in with a mixer.