Preheat the oven to 375 degrees.

In a mixing bowl whisk together flour, poppy seeds, baking powder, baking soda and salt.

In the bowl of an electric mixer, beat together the sugar, butter, lemon zest and oil on medium high speed until fluffy, about 4-5 minutes.

Add the eggs, one at a time, beating well after each addition. Stir in vanilla extract and lemon juice.

Using a spatula, gently stir in about ⅓ of the flour mixture. Add all of the buttermilk, stir, and then add another ⅓ of the flour mixture.

Stir in the sour cream, then end with the remaining flour mixture. The batter will be quite thick and a little lumpy looking.

Line muffin tins with 14 paper liners. Fill each cup 2/3 of the way full.

Use a teaspoon to create a small indent in each muffin and then fill it with a teaspoon of jam. Top with remaining batter.

Sprinkle with turbinado or sanding sugar, if desired, then bake in the preheated oven 20-25 minutes or until tops are firm and very light golden brown on the edges. Cool in the muffin tin for five minutes then transfer to a wire rack to cool completely or serve warm.