Preheat oven to 350 degrees F. Line large muffin tins with paper cups and spray lightly with nonstick spray.
In a small bowl, whisk together flour, sugars, lemon zest, lemon juice and salt. Stir in melted butter and almonds; mix with a fork until thoroughly combined to a crumble.
In the bowl of an electric mixer, combine eggs, sugar and oil. Beat at medium-high until thick and creamy, 6 minutes.
Stir in melted butter, lemon zest and juice until well combined.
In a medium bowl, whisk together flour, baking powder and salt. Gradually add flour mixture to butter mixture. Beat just until combined. Stir in sour cream and lemon curd and combine.
Pour mixture evenly among 6-7 large muffin cups. (I use a large ice cream scoop.)
Sprinkle with streusel mixture (There will be streusel left over. Freeze for a later use.)
Bake about 20-25 minutes. Remove from oven and punch holed in tops of muffins with a toothpick.
In a small saucepan, combine lemon juice and sugar. Bring to a slow boil and cook until slightly thickened.
Spoon syrup over hot muffins, allowing syrup to soak into muffins. Cool muffins in pan for 10 minutes. Remove to a wire rack or serve while warm.
