Warm butter in a saucepan over low heat or in the microwave until the butter is melted. Add milk. Stir and set aside to cool.
Set the oven rack in the middle position and preheat oven to 350 degrees. Butter and flour a 9 inch springform pan and set aside.
Whisk flour, almond flour, baking powder and salt in a medium bowl until fully combined. Set aside.
In the bowl of a stand mixer fitted with the paddle attachment, beat eggs and sugar together on medium-high speed until light in texture and pale yellow in color, about 2-3 minutes. Reduce speed to low and add vanilla.
Leave mixer speed on low and add ⅓ of the cooled butter and milk mixture followed by ⅓ of the flour mixture and mix until just combined. Repeat this process two more times ending with final ⅓ of the flour mixture.
Transfer the cake batter to prepared springform pan. Bake until golden brown and a tester poked into the center of the cake comes out clean, 35-45 minutes. Leave the cake in the pan and set it aside to cool slightly.
While the cake is cooling, make the topping. Set the oven to broil and make sure the oven rack is still in the middle position. Melt butter in a medium skillet over medium heat. Add almonds and fine salt and sauté until the almonds are just beginning to brown. Add the sugar and cream. Bring to a boil, stirring constantly. Boil until the mixture is slightly darker tan in color and is starting to thicken, about 2-3 minutes.
Pour the topping over the cake and broil until topping is nicely browned and bubbly. Keep a very close eye on it! This will happen in only a minute or so. I leave the oven door propped open so I can make sure it doesn’t get too dark. Remove from the oven. Sprinkle with sea salt. Allow the cake to cool in the pan.
Before serving, run a knife in between the cake and the edge of the pan to make sure that it is not sticking before you remove the sides of the springform pan. Cut into wedges and serve with whipped cream if desired.