Place 1.5 kg of peeled and cubed potatoes in a large pot.
Cover potatoes with salted water and bring to a boil.
Reduce heat to medium-low and simmer until tender, about 20 to 25 minutes.
Drain the potatoes and transfer to a bowl.
Mash potatoes with a potato masher or an electric mixer on low until smooth.
In a small saucepan, heat 1/2 cup butter and 1/2 cup half cream over medium heat.
Continue heating until butter is melted and half cream is warmed, about 3 to 5 minutes.
Mash or beat the butter mixture, 1 teaspoon salt, 1/4 teaspoon ground black pepper, and 1/4 teaspoon garlic powder into the mashed potatoes.
Continue mixing until potatoes are light and fluffy.
For a creamier consistency, stir additional half cream into potatoes, 1 tablespoon at a time.