Preheat oven to 350°F. Line a 12-cup muffin pan and spray with baking spray.
In a large bowl, beat together eggs, lemon zest, vanilla extract, and lavender extract until fluffy and light.
Add in granulated sugar and whip until fluffy and well combined.
Mix in vegetable oil and sour cream until smooth.
Sift in flour, baking powder, baking soda, and salt. Fold until just combined.
Use a cupcake scoop or measuring cup to fill cupcake liners two-thirds full. Drop onto counter from 3 inches high to eliminate air bubbles.
Bake in preheated oven 18-20 minutes or until centers are springy to the touch and a toothpick comes out with a few moist crumbs. Allow to cool completely before decorating.
Lemon Cream Cheese Buttercream Frosting
Using a hand mixer or in the bowl of a stand mixer with the whisk attachment, beat softened cream cheese and butter until smooth.
Mix in lemon zest and lemon juice until well combined.
Gradually add powdered sugar while continuing to mix until you've achieved your desired consistency. Beat an additional 1-2 minutes.
Spread or pipe over cooled cupcakes.
Freezing: These lavender lemon cupcakes are best frozen unfrosted -- just wrap each cooled cupcake in plastic wrap, then store in a freezer bag for up to 2 months. You can also freeze the frosted cupcakes too. Just freeze them uncovered until the frosting is solid, then wrap them in plastic wrap and place in an airtight container for up to 2 months. Thaw cupcakes unwrapped at room temperature.