Line two baking sheets with parchment paper and set aside.
Prepare cookie dough. In a large bowl mix butter with sugar and lemon zest until creamy. Add egg and mix until well combined. Mix in vanilla extract and sour cream.
In a medium bowl whisk together flour, baking powder and salt.
With mixer on low incorporate flour mixture to butter mixture.
Grease your hands with softened butter or oil. Scoop about 1 tbsp of dough and shape into balls. Place the balls on the prepared baking sheets.
Flatten the balls slightly .
Bake for 13-15 minutes until bottoms are lightly golden brown.
Remove form the oven and let cool completely.
When cookies are cooled use a small sharp knife to remove the cookie center crumb and place it in a bowl as it will be used for the filling.
Prepare the filling. Break the reserved cookie centers into crumbs. Add peach jam and ground pecans or walnuts over the reserved cookie crumbs and stir to combine.
Place the filling into a piping bag fitted with a plain tip (I’ve used a 9 mm tip).
Fill the cookies and match two cookies together.
Decorate cookies. Add about ⅓ cup peach liqueur into a small bowl. Ad yellow food coloring. Add another ⅓ cup peach liqueur into another bowl and add red food coloring. In another bowl add a bit of fine sugar.
Dip about a half of each sandwiched cookie into the yellow liqueur and then into the red one. Let it drain a bit and then roll into sugar to coat evenly.
Place the peach cookies onto a serving platter and decorate with green leaves if desired. Enjoy!