Preheat the oven to 350 degrees F. Line baking sheets with parchment paper. In a medium bowl, mix the flour, baking powder, baking soda, and salt.
Cream the butter and sugar together with an electric mixer until light and fluffy, 3+ minutes. Scrape the bowl and beat in the egg, lemon zest, lemon juice, vanilla, poppy seeds, and yellow food coloring. Turn the mixer on low and slowly add in the flour mixture. Scrape the bowl, then mix until well combined.
Scoop the cookie dough onto the baking sheets in 1 1/2-tablespoon portions, two inches apart. Sprinkle the tops with extra poppy seeds. Bake for 10-12 minutes, until the edges are just barely golden. Then cool on the cookie sheets for 5 minutes before moving.
Store in an airtight container at room temperature for up to a week.