Lemon Rosemary Crumb Cake - Do What Ema Says

Ingredients

• 2 Cups Unbleached Flour + 3/4 Cup unbleached flour for Crumb Topping
• 1 Teaspoon Salt
• 2 Teaspoons Baking Powder (aluminum-free)
• 1/2 Cup Unsalted Butter, room temp also 4 Tablespoons Unsalted Butter, melted for Crumb Topping
• 3 Lemons, zest & juice in 2 separate containers (about 2/3 for the for Cake & 1/3 for Crumb Topping)
• 3/4 Sugar (or a bit less) + 1/3 Cup Sugar for Crumb Topping
• 1 Egg, room temp
• 2 Teaspoons Vanilla
• 1/2 Cup Whole Milk + 1 1/2 Teaspoons Vinegar
• A bunch Fresh Rosemary, roughly chopped with a few sprigs left for garnish
• Confectioners Sugar