My Grandma's cake recipe/ Bolo Campineiro da Vo Lourdes

I was looking at some of my grandma's recipes, really old ones. So I decided to do this cake that I'm posting. It was supposed to be a breakfast cake without frosting, but I wanted to try a new frosting recipe from the Sono Cookbook, and I put some ganache for filling. The cake and frosting  are very buttery.
I thought this frosting recipe pretty good and easy, so I'm gonna share with you.
Frosting:
3 tbsp all purpose flour
1 cup milk
1 cup butter
1 cup sugar
pinch of coarse salt
1 t pure vanilla extract
In a saucepan, whisk the flor with 1/4 cup of milk, smoothing out any lumps with a rubber spatula. Gradually whisk in the rest of the milk.
Bring to a simmer over medium heat, whisking, and cook for 1 minute. Set aside to cool.
In the mixer with a paddle attachment, beat the butter,sugar, salt and vanilla until fluffy, about 2 minutes. Add the cooked milk mixture and beat until the frosting has consistency of whipped cream, 7 to 10 minutes.