Preheat oven to 350 F. Prepare twelve 8-ounce canning jars with vegetable pan spray and place on cookie pan.
In large bowl, combine flour, sugar, baking soda, baking powder and salt.
In medium bowl, whisk together sour cream, oil, eggs, lemon juice, lemon zest and vanilla. Add mixture to dry ingredients and stir until just combined. Stir in poppy seeds. Divide batter equally into jars.
Bake 24-26 minutes or until toothpick inserted in center of cake top comes out clean. Cool on pan on cooling grid 10 minutes. Remove jars from pan; cool completely on grid.
To assemble, spread thin layer of lemon curd over cake. Evenly divide 1/2 of the blueberries among jars. Spoon on whipped topping, smoothing with spatula; top with remaining blueberries.