Preheat the oven to 325 degrees F. Line 2 baking sheets with parchment paper. Fit 2 more baking sheets with a wire rack.
For the dough: In a stand mixer fitted with the paddle attachment, combine the granulated sugar, sour cream and vegetable oil on medium-low speed. Add the egg, vanilla extract and lemon oil and mix until combined. On low speed, add in the flour and baking powder and mix until a dough forms.
Remove the dough from the bowl onto a clean work surface dusted with flour. Knead until the dough forms a smooth ball. Using a bench scraper, cut the dough in quarters. Working with one quarter at a time, roll the dough into a snake about 1-inch thick. Using the bench scraper, cut the snake into 8 even pieces. Take one of the smaller pieces and roll into a snake again so that it is approximately 6 inches long. Knot the dough and place the prepared baking sheets with parchment. Repeat this process with the rest of the dough.
Bake the love knots for 10 to 12 minutes; they should turn a light golden brown on the bottom and double in size. Remove from the oven and let cool completely.
For the glaze: While the cookies are cooling, put the powdered sugar into a large bowl. Add the milk a little at a time until you reach the proper consistency; you want the icing to coat a spoon. Once the proper consistency, add the vanilla extract and lemon zest.
After the cookies have cooled completely, dip the entire cookie into the glaze. Hold the cookie over a bowl to allow excess glaze to run off and then place on the wire rack. Allow to dry for 30 seconds before sprinkling the tops with nonpareil sprinkles. Store the dried cookies in an airtight container to maintain freshness.