Start by lining your 9x5 inch loaf pan with parchment paper, leaving some overhang on the sides. This will make it easier to lift the bars out later.
In a microwave-safe bowl, combine 1 cup of semi-sweet chocolate chips and 1 tablespoon of vegetable oil. Microwave in 30-second intervals, stirring after each, until the chocolate is completely melted and smooth.
Pour half of the melted chocolate into the prepared loaf pan, spreading it evenly across the bottom. This will be the first layer of your Kit Kat bars.
Place 7 vanilla sugar wafers on top of the chocolate layer, side by side. Press them gently into the chocolate to help them stick.
Pour another layer of melted chocolate over the wafers, ensuring they are completely covered. Use the spatula to smooth it out.
Add another 7 wafers on top of the chocolate layer, pressing them down slightly. Pour the remaining melted chocolate over the top, ensuring that all the wafers are covered. Smooth the top with your spatula.
Refrigerate the loaf pan for about 1-2 hours or until the chocolate is completely set.
Once the chocolate has hardened, lift the bars out of the pan using the parchment paper overhang. Cut into rectangles to resemble Kit Kat bars. Enjoy your Homemade Kit Kat Bars!