Combine 250g flour, 0.5 teaspoon baking powder, 125g butter (cut into pieces), 80g sugar, 1 egg, 2 tablespoons cachaça, 1 teaspoon lime zest, and a pinch of salt in a mixing bowl.
Using a hand mixer with dough hook, mix until combined. Switch to kneading by hand for 2-3 minutes until the dough is smooth.
Refrigerate the dough for at least 1 hour.
When the dough has about 30 minutes of chilling remaining, roughly chop the 80g white chocolate.
Melt the chocolate in a hot water bath (place chocolate bowl over a pot of simmering water, not touching the water).
In a separate bowl, whip together 40g soft butter, the melted chocolate, 1 tablespoon powdered sugar, 3 tablespoons cachaça, 1 teaspoon lime zest, and 1 teaspoon lime juice for 2-3 minutes until creamy.
Cover the filling with cling film and set aside.
On a lightly floured surface, roll out the chilled dough to 3 mm thick.
Cut out 25-30 large heart shapes (5.5 cm diameter) and 25-30 small heart shapes (4 cm diameter) using a heart cutter.
Place hearts on baking sheets lined with parchment paper.
Bake in a preheated oven at 175°C (350°F) for 12-15 minutes until lightly golden.
Cool the hearts completely on a wire rack.
Spread 1 teaspoon of filling onto each large heart and top with a small heart.
Refrigerate for 30 minutes until the filling sets.
Mix 100g powdered sugar with 2 tablespoons lime juice to make a glaze.
Brush each heart generously with the glaze and decorate with lime peel strips.