Preheat your oven to 350°F (175°C). Grease a 9x5-inch loaf pan.
In a large mixing bowl, combine the flour, baking powder, and salt. Stir in the shredded cheddar cheese and chopped jalapeños until evenly distributed.
In a separate bowl, whisk together the milk, vegetable oil, and egg until well combined.
Pour the wet ingredients into the dry ingredients and stir until just combined. Do not overmix; a few lumps are okay.
Transfer the batter to the prepared loaf pan and smooth the top with a spatula.
Bake in the preheated oven for 45-50 minutes, or until a toothpick inserted into the center comes out clean.
Let the bread cool in the pan for about 10 minutes before transferring it to a wire rack to cool completely.