Start by pre-heating your oven to 350*F.

In a stand mixer, cream butter, sugar, lemon juice, and grated lemon zest together until fully incorporated.

Next, add in the eggs and beat until combined.

Add the flour and baking powder next, stirring slowly to combine (don't want to overmix once you add the flour).

In a small, dry saucepan on low heat, add the finely chopped macadamia nuts, toasting for 2-5 minutes until slightly golden brown and aromatic, before folding slowly into the cookie dough.

On a parchment lined baking sheet, drop by tablespoon-fulls into balls, and form into flattened, round disks in your hand (no thicker than 1/4-1/2 inch). Repeat process with remaining dough until no more is left.

Bake for 25-35 minutes at 350*F, or until cookies have begun to turn golden brown around the edges. An extra 5-10 minutes of baking time may need to be added, depending on your oven or settings.

Let cool on a drying rack until no longer warm to the touch, about 15-20 minutes.

Assembly Time! Match up cookies of about the same sizes to become tops and bottoms of your cookie sandwiches, spreading about a teaspoon-full of guava jam onto one side, and capping off with the other matching cookie. Repeat this process until you have no cookies left.

Keep in a Tupperware container or on a paper plate in a ziplock bag in the fridge for up to two weeks. Enjoy!