Prepare the chicken by patting it dry and pounding it to about ½-inch thickness so it cooks evenly.
Season both sides with salt, black pepper, and garlic powder.
Lightly coat each chicken breast in flour and shake off the excess.
Heat a large skillet over medium-high heat with olive oil and 2 tablespoons butter until hot and foamy.
Sear the chicken for about 3–4 minutes per side until golden and cooked through to 165°F (74°C), then transfer to a plate.
Cook the minced garlic in the same skillet for about 30 seconds until fragrant.
Pour in the white wine, scrape up the browned bits, and simmer for 1–2 minutes to reduce slightly.
Add the chicken broth and lemon juice and bring the sauce to a gentle simmer.
Stir in the drained capers and simmer for 3–5 minutes so the sauce reduces and becomes more flavorful.
Reduce the heat to low and stir in the remaining butter until the sauce is smooth and silky.
Return the chicken to the skillet and spoon the lemon-caper sauce over the top, warming it for 1–2 minutes.
Taste the sauce and adjust the seasoning carefully because the capers already add salt.
Garnish with fresh parsley and optional lemon slices.
Serve the chicken immediately with plenty of the warm piccata sauce spooned over each piece.